1. Manuals
  2. Brands
  3. Yamaha Manuals
  4. Scooter
  5. YP125R
  6. Service manual

Yamaha 2010 XMAX YP125R Service Manual

Mbk skycruiser
Hide thumbs Also See for 2010 XMAX YP125R:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
Table of Contents

Advertisement

Quick Links

See also: Owner's Manual
2010
SERVICE MANUAL
YP125R/YP250R
37P-F8197-E0

Advertisement

Table of Contents
loading

Related Manuals for Yamaha 2010 XMAX YP125R

Summary of Contents for Yamaha 2010 XMAX YP125R

  • Page 1 2010 SERVICE MANUAL YP125R/YP250R 37P-F8197-E0...
  • Page 2 EAS20060 YP125R/YP250R 2010 SERVICE MANUAL ©2009 by Yamaha Motor España, S.A. First edition, November 2009 All rights reserved. Any reproduction or unauthorized use without the written permission of Yamaha Motor España, S.A. is expressly prohibited.
  • Page 3 EAS20071 IMPORTANT This manual was produced by Yamaha Motor España, S.A. primarily for use by Yamaha and MBK deal- ers and their qualified mechanics. It is not possible to include all the knowledge of a mechanic in one manual. Therefore, anyone who uses this book to perform maintenance and repairs on Yamaha and MBK vehicles should have a basic understanding of mechanics and the techniques to repair these types of vehicles.

  • Page 4: How To Use This Manual

    EAS20090 HOW TO USE THIS MANUAL This manual is intended as a handy, easy-to-read reference book for the mechanic. Comprehensive explanations of all installation, removal, disassembly, assembly, repair and check procedures are laid out with the individual steps in sequential order. •...
  • Page 5 EAS20101 SYMBOLS The following symbols are used in this manual for easier understanding. The following symbols are not relevant to every vehicle. SYMBOL DEFINITION SYMBOL DEFINITION Serviceable with engine mounted Gear oil Filling fluid Molybdenum disulfide oil Lubricant Brake fluid Special tool Wheel bearing grease Tightening torque...

  • Page 7: Table Of Contents

    EAS20110 TABLE OF CONTENTS GENERAL INFORMATION SPECIFICATIONS PERIODIC CHECKS AND ADJUSTMENTS CHASSIS ENGINE COOLING SYSTEM FUEL SYSTEM ELECTRICAL SYSTEM TROUBLESHOOTING...

  • Page 9: General Information

    GENERAL INFORMATION IDENTIFICATION .................... 1-1 VEHICLE IDENTIFICATION NUMBER ............. 1-1 MODEL LABEL..................1-1 FEATURES...................... 1-2 OUTLINE OF THE FI SYSTEM..............1-2 FI SYSTEM....................1-3 INSTRUMENT FUNCTIONS................1-4 IMPORTANT INFORMATION ................. 1-8 PREPARATION FOR REMOVAL AND DISASSEMBLY......1-8 REPLACEMENT PARTS................1-8 GASKETS, OIL SEALS AND O-RINGS ............

  • Page 10: Identification

    IDENTIFICATION EAS20130 IDENTIFICATION EAS20140 VEHICLE IDENTIFICATION NUMBER The vehicle identification number “1” is stamped into the frame. EAS20150 MODEL LABEL The model label “1” is affixed to the location shown. This information will be needed to order spare parts.

  • Page 11: Features

    FEATURES EAS20170 FEATURES EAS37P1140 OUTLINE OF THE FI SYSTEM The main function of a fuel supply system is to provide fuel to the combustion chamber at the optimum air-fuel ratio in accordance with the engine operating conditions and the atmospheric temperature. In the conventional carburetor system, the air-fuel ratio of the mixture that is supplied to the combustion chamber is created by the volume of the intake air and the fuel that is metered by the jet used in the respective carburetor.

  • Page 12: Fi System

    FEATURES EAS37P1141 FI SYSTEM The fuel pump delivers fuel to the fuel injector via the fuel filter. The pressure regulator maintains the fuel pressure that is applied to the fuel injector at only 250 kPa (2.50 kgf/cm², 36.3 psi). Accordingly, when the energizing signal from the ECU energizes the fuel injector, the fuel passage opens, causing the fuel to be injected into the intake manifold only during the time the passage remains open.
  • Page 13 INSTRUMENT FUNCTIONS • a fuel reserve tripmeter (which shows the dis- EAS37P1080 INSTRUMENT FUNCTIONS tance traveled since the bottom segment of the fuel meter and fuel level warning indicator Multi-function display started flashing) EWA37P1016 • a self-diagnosis device WARNING • a clock Be sure to stop the vehicle before making •...

  • Page 14: Oil Change Indicator

    This indicator flashes at the initial 1000 km (600 mi), then at 6000 km (3500 mi) and every 6000 km (3500 mi) thereafter for YP125R, or at 4000 To reset a tripmeter, select it by pushing the “SE- km (2500 mi) and every 3000 km (1800 mi) LECT”...
  • Page 15 This indicator flashes every 18000 km (10500 light will flash and the multi-function display will mi) for the YP125R, or every 20000 km (12500 indicate a fault code when the key is turned to mi) for the YP250R, when the V-belt needs to be “ON”.

  • Page 16: Instrument Functions

    INSTRUMENT FUNCTIONS Immobilizer system keys may cause signal inter- “SELECT” button for at least two seconds ference, which may prevent the engine from switches the ambient temperature display to the starting. clock display. 2. If the engine starts, turn it off, and try starting •...

  • Page 17: Important Information

    5. Keep all parts away from any source of fire. EAS20200 REPLACEMENT PARTS Use only genuine Yamaha parts for all replace- ments. Use oil and grease recommended by Yamaha for all lubrication jobs. Other brands may be similar in function and appearance, but...

  • Page 18: Bearings And Oil Seals

    IMPORTANT INFORMATION EAS20230 BEARINGS AND OIL SEALS Install bearings “1” and oil seals “2” so that the manufacturer’s marks or numbers are visible. When installing oil seals, lubricate the oil seal lips with a light coat of lithium-soap-based grease. Oil bearings liberally when installing, if appropriate.

  • Page 19: Checking The Connections

    CHECKING THE CONNECTIONS EAS20250 CHECKING THE CONNECTIONS Pocket tester 90890-03112 Check the leads, couplers, and connectors for Analog pocket tester stains, rust, moisture, etc. YU-03112-C 1. Disconnect: • Lead • Coupler • If there is no continuity, clean the terminals. •...

  • Page 20: Special Tools

    SPECIAL TOOLS EAS20260 SPECIAL TOOLS The following special tools are necessary for complete and accurate tune-up and assembly. Use only the appropriate special tools as this will help prevent damage caused by the use of inappropriate tools or improvised techniques. Special tools, part numbers or both may differ depending on the country. When placing an order, refer to the list provided below to avoid any mistakes.
  • Page 21 T-handle 3/8" drive 60 cm long YM-01326 Fork seal driver weight 4-54 90890-01367 Replacement hammer YM-A9409-7 Fork seal driver attachment (ø38) 4-54 90890-01372 Replacement 38 mm YM-A5142-1 Yamaha bond No. 1215 5-12, 5-43, 90890-85505 5-59, 5-103, (Three Bond No.1215®) 5-120, 6-15 1-12...
  • Page 22 SPECIAL TOOLS Reference Tool name/Tool No. Illustration pages Valve spring compressor 5-19, 5-24, 90890-04019 5-78, 5-83 YM-04019 Valve spring compressor attachment 5-19, 5-24, 90890-04108 5-78, 5-83 Valve spring compressor adapter 22 mm YM-04108 Valve guide remover (ø4.5) 5-20 90890-04116 Valve guide remover (4.5 mm) YM-04116 Valve guide installer (ø4.5) 5-20...
  • Page 23 SPECIAL TOOLS Reference Tool name/Tool No. Illustration pages Locknut wrench 5-33, 5-37, 90890-01348 5-93, 5-97 YM-01348 Clutch spring holder 5-34, 5-37, 90890-01337 5-94, 5-97 Clutch spring holder arm 5-34, 5-37, 90890-01464 5-94, 5-97 Oil seal guide (ø41) 5-36, 5-96 90890-01396 Flywheel puller 5-41, 5-101 90890-01362...
  • Page 24 SPECIAL TOOLS Reference Tool name/Tool No. Illustration pages Crankcase separating tool 5-56, 5-117 90890-01135 Crankcase separator YU-01135-B Crankshaft installer pot 5-58, 5-59, 90890-01274 5-119, 5-120 Installing pot YU-90058 YU-90058/YU-90059 Crankshaft installer bolt 5-58, 5-59, 90890-01275 5-119, 5-120 Bolt YU-90060 Adapter (M14) 5-58, 5-59, 90890-01478 5-119...
  • Page 25 YM-04064-A Valve guide installer (ø6) 5-79 90890-04065 Valve guide installer (6.0 mm) YM-04065-A Valve guide reamer (ø6) 5-79 90890-04066 Valve guide reamer (6.0 mm) YM-04066 Yamaha grease G 5-91 90793-40016 Spacer (crankshaft installer) 5-119 90890-04081 Pot spacer YM-91044 YM-91044 1-16...
  • Page 26 SPECIAL TOOLS Reference Tool name/Tool No. Illustration pages Adapter (M16) 5-120 90890-01280 Adapter #7 YM-90067 Spacer 5-120 90890-01288 Mechanical seal installer 90890-04145 ø30 ø10 Middle driven shaft bearing driver 6-6, 6-15 90890-04058 Bearing driver 40 mm YM-04058 Mechanical seal installer 6-15 90890-04132 Water pump seal installer...
  • Page 27 SPECIAL TOOLS Reference Tool name/Tool No. Illustration pages Test harness-lean angle sensor (6P) 8-84 90890-03209 Test harness 8-89 90890-03204 1-18...
  • Page 28 SPECIAL TOOLS 1-19...

  • Page 29: Specifications

    TIGHTENING TORQUES (YP125R) ............. 2-15 GENERAL TIGHTENING TORQUE SPECIFICATIONS......2-15 ENGINE TIGHTENING TORQUES............2-16 CHASSIS TIGHTENING TORQUES............2-18 LUBRICATION POINTS AND LUBRICANT TYPES (YP125R)....2-21 ENGINE....................2-21 CHASSIS....................2-23 LUBRICATION SYSTEM DIAGRAMS (YP125R) ......... 2-25 COOLING SYSTEM DIAGRAMS (YP125R) ..........2-27 CABLE ROUTING (YP125R) ................
  • Page 30 COOLING SYSTEM DIAGRAMS (YP250R) ..........2-73 CABLE ROUTING (YP250R) ................ 2-75...

  • Page 32: General Specifications (Yp125R)

    GENERAL SPECIFICATIONS (YP125R) EAS37P1117 GENERAL SPECIFICATIONS (YP125R) Model Model 39D1 (YAMAHA) 39D3 (MBK) Dimensions Overall length 2201 mm (86.7 in) Overall width 776 mm (30.6 in) Overall height 1337 mm (52.6 in) Seat height 792 mm (31.2 in) Wheelbase 1545 mm (60.8 in) Ground clearance 134 mm (5.30 in)

  • Page 33: Engine Specifications (Yp125R)

    ENGINE SPECIFICATIONS (YP125R) EAS37P1118 ENGINE SPECIFICATIONS (YP125R) Engine Engine type Liquid cooled 4-stroke, SOHC Displacement 124 cm³ Cylinder arrangement Forward-inclined single cylinder Bore × stroke 52.0 × 58.6 mm (2.05 × 2.31 in) Compression ratio 11.20 :1 Standard compression pressure (at sea level) 550 kPa/680 r/min (5.5 kgf/cm²/680 r/min, 78.2...
  • Page 34 ENGINE SPECIFICATIONS (YP125R) Radiator cap opening pressure 100.0–120.0 kPa (1.00–1.20 kgf/cm², 14.5–17.4 psi) Thermostat Valve opening temperature 70.5–73.5 °C (158.9–164.3 °F) Valve full open temperature 85.0 °C (185.0 °F) Valve lift (full open) 3.0 mm (0.12 in) Radiator core Width 244.0 mm (9.61 in)
  • Page 35 ENGINE SPECIFICATIONS (YP125R) Camshaft runout limit 0.030 mm (0.0012 in) Timing chain Tensioning system Automatic Rocker arm/rocker arm shaft Rocker arm inside diameter 9.985–10.000 mm (0.3931–0.3937 in) Limit 10.015 mm (0.3943 in) Rocker arm shaft outside diameter 9.966–9.976 mm (0.3924–0.3928 in) Limit 9.940 mm (0.3913 in)
  • Page 36 ENGINE SPECIFICATIONS (YP125R) Limit 0.5 mm (0.02 in) Valve stem diameter (intake) 4.475–4.490 mm (0.1762–0.1768 in) Limit 4.445 mm (0.1750 in) Valve stem diameter (exhaust) 4.460–4.475 mm (0.1756–0.1762 in) Limit 4.430 mm (0.1744 in) Valve guide inside diameter (intake) 4.500–4.512 mm (0.1772–0.1776 in) Limit 4.550 mm (0.1791 in)
  • Page 37 ENGINE SPECIFICATIONS (YP125R) Winding direction (intake) Clockwise Winding direction (exhaust) Clockwise Cylinder Bore 52.000–52.010 mm (2.0472–2.0476 in) Wear limit 52.110 mm (2.0516 in) Taper limit 0.050 mm (0.0020 in) Out of round limit 0.005 mm (0.0002 in) Warp limit 0.05 mm (0.0020 in)
  • Page 38 ENGINE SPECIFICATIONS (YP125R) Limit 0.60 mm (0.0236 in) Ring side clearance 0.030–0.070 mm (0.0012–0.0028 in) Limit 0.120 mm (0.0047 in) Oil ring Dimensions (B × T) 1.50 × 1.95 mm (0.06 × 0.08 in) End gap (installed) 0.20–0.70 mm (0.0079–0.0276 in) Ring side clearance 0.060–0.150 mm (0.0024–0.0059 in)
  • Page 39 ENGINE SPECIFICATIONS (YP125R) Secondary reduction ratio 44/13 (3.385) Operation Centrifugal automatic type Gear ratio 2.645–0.824 :1 Decompression device Device type Auto decomp Air filter Air filter element Oil-coated paper element Fuel pump Pump type Electrical Output pressure 250.0 kPa (2.50 kgf/cm², 36.3 psi)

  • Page 40: Chassis Specifications (Yp125R)

    CHASSIS SPECIFICATIONS (YP125R) EAS37P1119 CHASSIS SPECIFICATIONS (YP125R) Chassis Frame type Steel tube underbone Caster angle 28.00° Trail 100.0 mm (3.94 in) Front wheel Wheel type Cast wheel 15 × MT3.5 Rim size Rim material Aluminum Wheel travel 110.0 mm (4.33 in) Radial wheel runout limit 1.0 mm (0.04 in)
  • Page 41 CHASSIS SPECIFICATIONS (YP125R) Front disc brake Disc outside diameter × thickness 267.0 × 5.0 mm (10.51 × 0.20 in) Brake disc thickness limit 4.5 mm (0.18 in) Brake disc deflection limit 0.15 mm (0.0059 in) Brake pad lining thickness (inner) 5.0 mm (0.20 in)
  • Page 42 CHASSIS SPECIFICATIONS (YP125R) Rear suspension Type Unit swing Spring/shock absorber type Coil spring/oil damper Rear shock absorber assembly travel 95.0 mm (3.74 in) Spring free length 274.0 mm (10.79 in) Installed length 241.3 mm (9.50 in) Spring rate K1 8.00 N/mm (0.82 kgf/mm, 45.68 lb/in) Spring rate K2 17.30 N/mm (1.76 kgf/mm, 98.78 lb/in)

  • Page 43: Electrical Specifications (Yp125R)

    ELECTRICAL SPECIFICATIONS (YP125R) EAS37P1120 ELECTRICAL SPECIFICATIONS (YP125R) Voltage System voltage 12 V Ignition system Ignition system TCI (digital) Advancer type Digital Ignition timing (B.T.D.C.) 8.0°/1700 r/min Engine control unit Model/manufacturer 39D0/YAMAHA Ignition coil Minimum ignition spark gap 6.0 mm (0.24 in) 2.16–2.64 Ω...
  • Page 44 ELECTRICAL SPECIFICATIONS (YP125R) Indicator lights 12 V, 1.4 W × 2 Turn signal indicator light 12 V, 1.4 W × 1 High beam indicator light 12 V, 1.4 W × 1 Engine trouble warning light Immobilizer system indicator light Electric starting system...
  • Page 45 ELECTRICAL SPECIFICATIONS (YP125R) Spare fuse 15.0 A Spare fuse 10.0 A Spare fuse 5.0 A Spare fuse 7.5 A 2-14...

  • Page 46: Tightening Torques (Yp125R)

    TIGHTENING TORQUES (YP125R) EAS37P1121 TIGHTENING TORQUES (YP125R) EAS37P1123 GENERAL TIGHTENING TORQUE SPECIFICATIONS This chart specifies tightening torques for stan- dard fasteners with a standard ISO thread pitch. Tightening torque specifications for special com- ponents or assemblies are provided for each chapter of this manual.

  • Page 47: Engine Tightening Torques

    TIGHTENING TORQUES (YP125R) EAS37P1122 ENGINE TIGHTENING TORQUES Thread Item Q’ty Tightening torque Remarks size Exhaust pipe nut 20 Nm (2.0 m·kgf, 14 ft·lbf) Muffler bolt 53 Nm (5.3 m·kgf, 38 ft·lbf) Muffler joint bolt 14 Nm (1.4 m·kgf, 10 ft·lbf) sensor 45 Nm (4.5 m·kgf, 32 ft·lbf)
  • Page 48 TIGHTENING TORQUES (YP125R) Thread Item Q’ty Tightening torque Remarks size Engine oil drain bolt 20 Nm (2.0 m·kgf, 14 ft·lbf) Final transmission oil drain bolt 20 Nm (2.0 m·kgf, 14 ft·lbf) Crankcase bolt 10 Nm (1.0 m·kgf, 7.2 ft·lbf) Timing chain guide bolt (intake 7 Nm (0.7 m·kgf, 5.1 ft·lbf)

  • Page 49: Chassis Tightening Torques

    TIGHTENING TORQUES (YP125R) EAS37P1124 CHASSIS TIGHTENING TORQUES Thread Item Q’ty Tightening torque Remarks size Engine bracket nut 59 Nm (5.9 m·kgf, 43 ft·lbf) Engine bracket rod nut 64 Nm (6.4 m·kgf, 46 ft·lbf) Engine mounting nut 43 Nm (4.3 m·kgf, 31 ft·lbf) Radiator bolt 10 Nm (1.0 m·kgf, 7.2 ft·lbf)
  • Page 50 TIGHTENING TORQUES (YP125R) Thread Item Q’ty Tightening torque Remarks size Front brake hose holder bolt 7 Nm (0.7 m·kgf, 5.1 ft·lbf) Front brake caliper bleed screw 6 Nm (0.6 m·kgf, 4.3 ft·lbf) Front brake pad pin cap 3 Nm (0.3 m·kgf, 2.2 ft·lbf) Front brake pad pin 18 Nm (1.8 m·kgf, 13 ft·lbf)
  • Page 51 TIGHTENING TORQUES (YP125R) Lower ring nut 1. Tighten the lower ring nut 38 Nm (3.8 m·kgf, 27 ft·lbf) with a torque wrench and the steering nut wrench, and then loosen the nut 1/4 turn. 2. Tighten the lower ring nut 22 Nm (2.2 m·kgf, 16 ft·lbf) with a torque wrench and the steering nut wrench.

  • Page 52: Lubrication Points And Lubricant Types (Yp125R)

    LUBRICATION POINTS AND LUBRICANT TYPES (YP125R) EAS37P1125 LUBRICATION POINTS AND LUBRICANT TYPES (YP125R) EAS37P1126 ENGINE Lubrication point Lubricant Oil seal lips O-rings Bearings Cylinder head nut mounting surface Crankshaft pin Connecting rod big end thrust surface Oil pump drive gear inner surface...
  • Page 53 LUBRICATION POINTS AND LUBRICANT TYPES (YP125R) Lubrication point Lubricant Yamaha bond Timing chain tensioner bolt No.1215® 2-22...

  • Page 54: Chassis

    LUBRICATION POINTS AND LUBRICANT TYPES (YP125R) EAS37P1127 CHASSIS Lubrication point Lubricant Drive axle Swingarm oil seal lips Steering bearings (upper and lower) Seat hinge pin Front wheel oil seal lip and front wheel axle Speed sensor oil seal lip Brake lever pivoting point and metal-to-metal moving parts...
  • Page 55 LUBRICATION POINTS AND LUBRICANT TYPES (YP125R) 2-24...

  • Page 56: Lubrication System Diagrams (Yp125R)

    LUBRICATION SYSTEM DIAGRAMS (YP125R) EAS37P1139 LUBRICATION SYSTEM DIAGRAMS (YP125R) 2-25...
  • Page 57 LUBRICATION SYSTEM DIAGRAMS (YP125R) 1. Camshaft 2. Crankshaft 3. Oil pump 4. Oil filter 5. Oil strainer 2-26...

  • Page 58: Cooling System Diagrams (Yp125R)

    COOLING SYSTEM DIAGRAMS (YP125R) EAS37P1128 COOLING SYSTEM DIAGRAMS (YP125R) 2-27...
  • Page 59 COOLING SYSTEM DIAGRAMS (YP125R) 1. Coolant reservoir 2. Coolant reservoir hose 3. Radiator cap 4. Radiator filler hose 5. Radiator 6. Radiator inlet hose 7. Radiator outlet hose 2-28...

  • Page 60: Cable Routing (Yp125R)

    CABLE ROUTING (YP125R) EAS37P1129 CABLE ROUTING (YP125R) Battery (front view) 2-29...
  • Page 61 CABLE ROUTING (YP125R) 1. Positive battery lead 2. Meter assembly lead 3. Self-diagnosis signal lead 4. Fuse box 1 5. Air temperature sensor lead 6. Fuse box 2 7. Starter relay lead 8. Negative battery lead 9. Headlight lead 10. Wire harness 11.
  • Page 62 CABLE ROUTING (YP125R) Front fork (front view) 2-31...
  • Page 63 CABLE ROUTING (YP125R) 1. Speed sensor lead 2. Front brake hose 3. Rectifier/regulator 4. Left front turn signal light coupler 5. Wire harness 6. Horn 7. Right front turn signal light coupler A. Point the end of the plastic locking tie forward, and –...
  • Page 64 CABLE ROUTING (YP125R) Front brake hose (right side view) 2-33...
  • Page 65 CABLE ROUTING (YP125R) 1. Front brake hose 2. Radiator fan motor relay 3. Starting circuit cut-off relay 4. Speed sensor lead 5. Right front turn signal light 6. Radiator fan motor 7. Radiator fan motor lead 8. Wire harness 9. Rear brake pipe 10.
  • Page 66 CABLE ROUTING (YP125R) Engine (right side view) 2-35...
  • Page 67 CABLE ROUTING (YP125R) 1. Seat lock cable 2. Wire harness 3. Ignition coil lead 4. Spark plug cap 5. O sensor 6. Starter motor lead 7. Rear brake hose A. Point the end of the plastic locking tie to the right, –...
  • Page 68 CABLE ROUTING (YP125R) Throttle cables (left side view) 2-37...
  • Page 69 CABLE ROUTING (YP125R) 1. Meter assembly 2. ECU (engine control unit) 3. Seat lock cable 4. Immobilizer unit coupler 5. Throttle cables 6. Wire harness 7. Sidestand switch lead 8. Rear brake hose 9. Front brake hose 10. Left front turn signal light lead 11.
  • Page 70 CABLE ROUTING (YP125R) Engine (left side view) 2-39...
  • Page 71 CABLE ROUTING (YP125R) 1. Wire harness 2. Intake air temperature sensor 3. Seat lock cable 4. Left tail/brake light assembly A. Point the end of the plastic locking tie to the left, – and then cut off the excess end of the tie to 0 –...
  • Page 72 CABLE ROUTING (YP125R) Handlebar (top view) 2-41...
  • Page 73 CABLE ROUTING (YP125R) 1. Radiator fan motor relay 2. Starting circuit cut-off relay 3. Headlight relay 4. Right handlebar switch lead 5. Front brake hose 6. Fuel pump coupler 7. Fuel sender coupler 8. Fuel hose 9. Left handlebar switch lead 10.
  • Page 74 CABLE ROUTING (YP125R) Throttle body (top view) 2-43...
  • Page 75 CABLE ROUTING (YP125R) 1. Rear brake pipe 2. Crankshaft position sensor/stator assembly lead 3. Wire harness 4. ISC (idle speed control) unit coupler 5. Ground lead 6. Intake air temperature sensor coupler 7. Intake air pressure sensor coupler 8. Seat lock cable 9.
  • Page 76 CABLE ROUTING (YP125R) Tail/brake light (top view) 2-45...
  • Page 77 CABLE ROUTING (YP125R) 1. Wire harness 2. Rear brake hose 3. License plate light lead 4. Right tail/brake light assembly coupler 5. Left tail/brake light assembly coupler 6. Seat lock cable A. Point the end of the plastic locking tie to the right, –...

  • Page 78: General Specifications (Yp250R)

    GENERAL SPECIFICATIONS (YP250R) EAS20280 GENERAL SPECIFICATIONS (YP250R) Model Model 37P1 (YAMAHA) Dimensions Overall length 2201 mm (86.7 in) Overall width 776 mm (30.6 in) Overall height 1337 mm (52.6 in) Seat height 792 mm (31.2 in) Wheelbase 1545 mm (60.8 in) Ground clearance 134 mm (5.30 in)

  • Page 79: Engine Specifications (Yp250R)

    ENGINE SPECIFICATIONS (YP250R) EAS20290 ENGINE SPECIFICATIONS (YP250R) Engine Engine type Liquid cooled 4-stroke, SOHC Displacement 249 cm³ Cylinder arrangement Forward-inclined single cylinder Bore × stroke 69.0 × 66.8 mm (2.72 × 2.63 in) Compression ratio 10.00 :1 Standard compression pressure (at sea level) 1400 kPa/500 r/min (14.0 kgf/cm²/500 r/min, 199.1 psi/500 r/min) Minimum–maximum...
  • Page 80 ENGINE SPECIFICATIONS (YP250R) Thermostat Valve opening temperature 80.5–83.5 °C (176.9–182.3 °F) Valve full open temperature 93.0–97.0 °C (199.4–206.6 °F) Valve lift (full open) 3.0 mm (0.12 in) Radiator core Width 244.0 mm (9.61 in) Height 128.9 mm (5.07 in) Depth 22.0 mm (0.87 in) Water pump Water pump type...
  • Page 81 ENGINE SPECIFICATIONS (YP250R) Timing chain Tensioning system Automatic Rocker arm/rocker arm shaft Rocker arm inside diameter 12.000–12.018 mm (0.4724–0.4731 in) Limit 12.030 mm (0.4736 in) Rocker arm shaft outside diameter 11.981–11.991 mm (0.4717–0.4721 in) Limit 11.950 mm (0.4705 in) Rocker-arm-to-rocker-arm-shaft clearance 0.009–0.037 mm (0.0004–0.0015 in) Limit 0.080 mm (0.0031 in)
  • Page 82 ENGINE SPECIFICATIONS (YP250R) Valve guide inside diameter (intake) 6.000–6.012 mm (0.2362–0.2367 in) Limit 6.050 mm (0.2382 in) Valve guide inside diameter (exhaust) 6.000–6.012 mm (0.2362–0.2367 in) Limit 6.050 mm (0.2382 in) Valve-stem-to-valve-guide clearance (intake) 0.010–0.037 mm (0.0004–0.0015 in) Limit 0.080 mm (0.0031 in) Valve-stem-to-valve-guide clearance (exhaust) 0.025–0.052 mm (0.0010–0.0020 in) Limit...
  • Page 83 ENGINE SPECIFICATIONS (YP250R) Spring rate K1 (intake) 23.18 N/mm (2.36 kgf/mm, 132.36 lb/in) Spring rate K2 (intake) 31.66 N/mm (3.23 kgf/mm, 180.78 lb/in) Spring rate K1 (exhaust) 23.18 N/mm (2.36 kgf/mm, 132.36 lb/in) Spring rate K2 (exhaust) 31.66 N/mm (3.23 kgf/mm, 180.78 lb/in) Installed compression spring force (intake) 115–133 N (11.73–13.56 kgf, 25.85–29.90 lbf) Installed compression spring force (exhaust)
  • Page 84 ENGINE SPECIFICATIONS (YP250R) Dimensions (B × T) 1.00 × 2.60 mm (0.04 × 0.10 in) End gap (installed) 0.15–0.30 mm (0.0059–0.0118 in) Limit 0.55 mm (0.0217 in) Ring side clearance 0.040–0.080 mm (0.0016–0.0031 in) Limit 0.130 mm (0.0051 in) 2nd ring Ring type Taper Dimensions (B ×...
  • Page 85 ENGINE SPECIFICATIONS (YP250R) Clutch shoe spring free length 40.5 mm (1.59 in) Clutch housing inside diameter 145.0 mm (5.71 in) Limit 145.5 mm (5.73 in) Compression spring free length 102.4 mm (4.03 in) Limit 90.0 mm (3.54 in) Weight outside diameter 20.0 mm (0.79 in) Limit 19.5 mm (0.77 in)
  • Page 86 ENGINE SPECIFICATIONS (YP250R) Water temperature 85.0–95.0 °C (185.00–203.00 °F) Oil temperature 75.0–85.0 °C (167.00–185.00 °F) Throttle cable free play 3.0–5.0 mm (0.12–0.20 in) 2-55...

  • Page 87: Chassis Specifications (Yp250R)

    CHASSIS SPECIFICATIONS (YP250R) EAS20300 CHASSIS SPECIFICATIONS (YP250R) Chassis Frame type Steel tube underbone Caster angle 28.00° Trail 100.0 mm (3.94 in) Front wheel Wheel type Cast wheel 15 × MT3.5 Rim size Rim material Aluminum Wheel travel 110.0 mm (4.33 in) Radial wheel runout limit 1.0 mm (0.04 in) Lateral wheel runout limit...
  • Page 88 CHASSIS SPECIFICATIONS (YP250R) Front disc brake Disc outside diameter × thickness 267.0 × 5.0 mm (10.51 × 0.20 in) Brake disc thickness limit 4.5 mm (0.18 in) Brake disc deflection limit 0.15 mm (0.0059 in) Brake pad lining thickness (inner) 5.0 mm (0.20 in) Limit 1.5 mm (0.06 in)
  • Page 89 CHASSIS SPECIFICATIONS (YP250R) Rear suspension Type Unit swing Spring/shock absorber type Coil spring/oil damper Rear shock absorber assembly travel 95.0 mm (3.74 in) Spring free length 274.0 mm (10.79 in) Installed length 241.3 mm (9.50 in) Spring rate K1 8.00 N/mm (0.82 kgf/mm, 45.68 lb/in) Spring rate K2 17.30 N/mm (1.76 kgf/mm, 98.78 lb/in) Spring stroke K1...

  • Page 90: Electrical Specifications (Yp250R)

    TCI (digital) Advancer type Digital Ignition timing (B.T.D.C.) 10.0°/1550 r/min Engine control unit Model/manufacturer 37P0/YAMAHA Ignition coil Minimum ignition spark gap 6.0 mm (0.24 in) 2.16–2.64 Ω at 20 °C (68 °F) Primary coil resistance Secondary coil resistance 8.64–12.96 kΩ at 20 °C (68 °F)
  • Page 91 ELECTRICAL SPECIFICATIONS (YP250R) Indicator lights 12 V, 1.4 W × 2 Turn signal indicator light 12 V, 1.4 W × 1 High beam indicator light 12 V, 1.4 W × 1 Engine trouble warning light Immobilizer system indicator light Electric starting system System type Constant mesh Starter motor...
  • Page 92 ELECTRICAL SPECIFICATIONS (YP250R) Spare fuse 15.0 A Spare fuse 10.0 A Spare fuse 5.0 A Spare fuse 7.5 A 2-61...

  • Page 93: Tightening Torques (Yp250R)

    TIGHTENING TORQUES (YP250R) EAS20320 TIGHTENING TORQUES (YP250R) EAS20330 GENERAL TIGHTENING TORQUE SPECIFICATIONS This chart specifies tightening torques for stan- dard fasteners with a standard ISO thread pitch. Tightening torque specifications for special com- ponents or assemblies are provided for each chapter of this manual.

  • Page 94: Engine Tightening Torques

    TIGHTENING TORQUES (YP250R) EAS20340 ENGINE TIGHTENING TORQUES Thread Item Q’ty Tightening torque Remarks size Exhaust pipe nut 20 Nm (2.0 m·kgf, 14 ft·lbf) Muffler bolt 53 Nm (5.3 m·kgf, 38 ft·lbf) Muffler joint bolt 14 Nm (1.4 m·kgf, 10 ft·lbf) sensor 45 Nm (4.5 m·kgf, 32 ft·lbf) Oil check bolt...
  • Page 95 TIGHTENING TORQUES (YP250R) Thread Item Q’ty Tightening torque Remarks size Oil pump assembly bolt 7 Nm (0.7 m·kgf, 5.1 ft·lbf) Transmission case cover bolt 16 Nm (1.6 m·kgf, 11 ft·lbf) Oil strainer cover 32 Nm (3.2 m·kgf, 23 ft·lbf) Engine oil drain bolt 20 Nm (2.0 m·kgf, 14 ft·lbf) Final transmission oil drain bolt 22 Nm (2.2 m·kgf, 16 ft·lbf)
  • Page 96 TIGHTENING TORQUES (YP250R) Cylinder head tightening sequence: Muffler tightening sequence: 2-65...

  • Page 97: Chassis Tightening Torques

    TIGHTENING TORQUES (YP250R) EAS20350 CHASSIS TIGHTENING TORQUES Thread Item Q’ty Tightening torque Remarks size Engine bracket nut 59 Nm (5.9 m·kgf, 43 ft·lbf) Engine bracket rod nut 64 Nm (6.4 m·kgf, 46 ft·lbf) Engine mounting nut 43 Nm (4.3 m·kgf, 31 ft·lbf) Radiator bolt 10 Nm (1.0 m·kgf, 7.2 ft·lbf) Filler neck bolt...
  • Page 98 TIGHTENING TORQUES (YP250R) Thread Item Q’ty Tightening torque Remarks size Front brake hose holder bolt 7 Nm (0.7 m·kgf, 5.1 ft·lbf) Front brake caliper bleed screw 6 Nm (0.6 m·kgf, 4.3 ft·lbf) Front brake pad pin cap 3 Nm (0.3 m·kgf, 2.2 ft·lbf) Front brake pad pin 18 Nm (1.8 m·kgf, 13 ft·lbf) Front brake caliper retaining pin...
  • Page 99 TIGHTENING TORQUES (YP250R) Lower ring nut 1. Tighten the lower ring nut 38 Nm (3.8 m·kgf, 27 ft·lbf) with a torque wrench and the steering nut wrench, and then loosen the nut 1/4 turn. 2. Tighten the lower ring nut 22 Nm (2.2 m·kgf, 16 ft·lbf) with a torque wrench and the steering nut wrench.

  • Page 100: Lubrication Points And Lubricant Types (Yp250R)

    Starter clutch gear thrust surface Starter clutch gear inner surface Main axle thrust surfaces Main axle serration Drive axle serration BEL-RAY assembly Oil seal (secondary sliding sheave) lube® BEL-RAY assembly O-ring and collar (clutch housing) lube® Yamaha bond Crankcase mating surfaces No.1215 2-69...
  • Page 101 LUBRICATION POINTS AND LUBRICANT TYPES (YP250R) Lubrication point Lubricant Yamaha bond No. Crankshaft position sensor/stator assembly lead grommet 1215 2-70...

  • Page 102: Chassis

    LUBRICATION POINTS AND LUBRICANT TYPES (YP250R) EAS20380 CHASSIS Lubrication point Lubricant Drive axle Swingarm oil seal lips Steering bearings (upper and lower) Seat hinge pin Front wheel oil seal lip and front wheel axle Speed sensor oil seal lip Brake lever pivoting point and metal-to-metal moving parts Rear brake caliper retaining bolt Throttle cable end Throttle grip inner surface and throttle cables...
  • Page 103 LUBRICATION POINTS AND LUBRICANT TYPES (YP250R) 2-72...
  • Page 104 COOLING SYSTEM DIAGRAMS (YP250R) EAS20420 COOLING SYSTEM DIAGRAMS (YP250R) 2-73...
  • Page 105 COOLING SYSTEM DIAGRAMS (YP250R) 1. Coolant reservoir 2. Coolant reservoir hose 3. Radiator cap 4. Radiator filler hose 5. Radiator 6. Radiator inlet hose 7. Radiator outlet hose 2-74...
  • Page 106 CABLE ROUTING (YP250R) EAS20430 CABLE ROUTING (YP250R) Battery (front view) 2-75...
  • Page 107 CABLE ROUTING (YP250R) 1. Positive battery lead 2. Meter assembly lead 3. Self-diagnosis signal lead 4. Fuse box 1 5. Air temperature sensor lead 6. Fuse box 2 7. Starter relay lead 8. Negative battery lead 9. Headlight lead 10. Wire harness 11.
  • Page 108 CABLE ROUTING (YP250R) Front fork (front view) 2-77...
  • Page 109 CABLE ROUTING (YP250R) 1. Speed sensor lead 2. Front brake hose 3. Rectifier/regulator 4. Left front turn signal light coupler 5. Wire harness 6. Horn 7. Right front turn signal light coupler A. Point the end of the plastic locking tie forward, and –...
  • Page 110 CABLE ROUTING (YP250R) Front brake hose (right side view) 2-79...
  • Page 111 CABLE ROUTING (YP250R) 1. Front brake hose 2. Radiator fan motor relay 3. Starting circuit cut-off relay 4. Speed sensor lead 5. Right front turn signal light 6. Radiator fan motor 7. Radiator fan motor lead 8. Wire harness 9. Rear brake pipe 10.
  • Page 112 CABLE ROUTING (YP250R) Engine (right side view) 2-81...
  • Page 113 CABLE ROUTING (YP250R) 1. Seat lock cable 2. Wire harness 3. Ignition coil lead 4. Spark plug cap 5. Coolant temperature sensor lead 6. O sensor 7. Starter motor lead 8. Rear brake hose A. Fasten the wire harness, starter motor lead, crankshaft position sensor/stator assembly lead, and O sensor lead with a plastic locking tie.
  • Page 114 CABLE ROUTING (YP250R) Throttle cables (left side view) 2-83...
  • Page 115 CABLE ROUTING (YP250R) 1. Meter assembly 2. ECU (engine control unit) 3. Seat lock cable 4. Immobilizer unit coupler 5. Throttle cables 6. Wire harness 7. Sidestand switch lead 8. Rear brake hose 9. Front brake hose 10. Left front turn signal light lead 11.
  • Page 116 CABLE ROUTING (YP250R) Engine (left side view) 2-85...
  • Page 117 CABLE ROUTING (YP250R) 1. Wire harness 2. Intake air temperature sensor 3. Seat lock cable 4. Left tail/brake light assembly 5. Safety protector 6. O sensor 7. Spark plug cap A. Route the left tail/brake light assembly lead and right tail/brake light assembly lead over the safety protector.
  • Page 118 CABLE ROUTING (YP250R) Handlebar (top view) 2-87...
  • Page 119 CABLE ROUTING (YP250R) 1. Radiator fan motor relay 2. Starting circuit cut-off relay 3. Headlight relay 4. Right handlebar switch lead 5. Front brake hose 6. Fuel pump coupler 7. Fuel sender coupler 8. Fuel hose 9. Left handlebar switch lead 10.
  • Page 120 CABLE ROUTING (YP250R) Throttle body (top view) 2-89...
  • Page 121 CABLE ROUTING (YP250R) 1. Rear brake pipe 2. Intake air pressure sensor coupler 3. Wire harness 4. Starter motor lead 5. Ground lead 6. Breather hose (air filter case to throttle body) 7. Intake air temperature sensor coupler 8. Fuel injector lead 9.
  • Page 122 CABLE ROUTING (YP250R) Tail/brake light (top view) 2-91...
  • Page 123 CABLE ROUTING (YP250R) 1. Wire harness 2. Rear brake hose 3. License plate light lead 4. Right tail/brake light assembly coupler 5. Left tail/brake light assembly coupler 6. Seat lock cable 7. Cylinder head breather hose 8. Intake air temperature sensor coupler A.
  • Page 124 CABLE ROUTING (YP250R) 2-93...

  • Page 125: Periodic Checks And Adjustments

    INTRODUCTION ..................3-1 PERIODIC MAINTENANCE CHART FOR THE EMISSION CONTROL SYSTEM (YP125R) .................. 3-1 GENERAL MAINTENANCE AND LUBRICATION CHART (YP125R) ..3-1 PERIODIC MAINTENANCE CHART FOR THE EMISSION CONTROL SYSTEM (YP250R) .................. 3-3 GENERAL MAINTENANCE AND LUBRICATION CHART (YP250R) ..3-3 ENGINE (YP125R)...................
  • Page 126 CHASSIS ....................... 3-35 CHECKING THE BRAKE FLUID LEVEL..........3-35 CHECKING THE FRONT BRAKE PADS ..........3-35 CHECKING THE REAR BRAKE PADS (YP125R)........3-35 CHECKING THE REAR BRAKE PADS (YP250R)........3-36 CHECKING THE FRONT BRAKE HOSE..........3-36 CHECKING THE REAR BRAKE HOSE ..........3-36 BLEEDING THE HYDRAULIC BRAKE SYSTEM ........

  • Page 128: Periodic Maintenance

    UK, a mileage-based maintenance, is performed instead. • From 30000 km (17500 mi), repeat the maintenance intervals starting from 6000 km (3500 mi). • Items marked with an asterisk should be performed by a Yamaha dealer as they require special tools, data and technical skills.
  • Page 129 PERIODIC MAINTENANCE ODOMETER READING CHECK OR MAINTENANCE ANNUAL ITEM CHECK 1000 km 6000 km 12000 km 18000 km 24000 km (600 mi) (3500 mi) (7000 mi) (10500 mi) (14000 mi) √ √ √ √ √ • Check for cracks or damage. 5 * Brake hoses •...

  • Page 130: Periodic Maintenance Chart For The Emission Control System (Yp250R)

    UK, a milage-based maintenance, is performed instead. • From 50000 km (30000 mi), repeat the maintenance intervals starting from 10000 km (6000 mi). • Items marked with an asterisk should be performed by a Yamaha dealer as they require special tools, data and technical skills.
  • Page 131 PERIODIC MAINTENANCE ODOMETER READING CHECK OR MAINTENANCE ANNUAL ITEM CHECK 1000 km 10000 km 20000 km 30000 km 40000 km (600 mi) (6000 mi) (12000 mi) (18000 mi) (24000 mi) • Check operation, fluid level √ √ √ √ √ √...
  • Page 132 PERIODIC MAINTENANCE EAU38262 • Engine air filter and V-belt air filters • This model’s engine air filter is equipped with a disposable oil-coated paper element, which must not be cleaned with compressed air to avoid damaging it. • The engine air filter element needs to be replaced and the V-belt air filter element needs to be ser- viced more frequently when riding in unusually wet or dusty areas.

  • Page 133: Engine (Yp125R)

    ENGINE (YP125R) EAS37P1087 ENGINE (YP125R) EAS37P1088 ADJUSTING THE VALVE CLEARANCE The following procedure applies to all of the valves. • Valve clearance adjustment should be made on a cold engine, at room temperature. • When the valve clearance is to be measured or 4.
  • Page 134 ENGINE (YP125R) c. Turn the adjusting screw “3” in direction “a” or “b” with the tappet adjusting tool “4” until the specified valve clearance is obtained. Direction “a” Valve clearance is increased. Direction “b” Valve clearance is decreased. Tappet adjusting tool c.

  • Page 135: Adjusting The Exhaust Gas Volume

    ENGINE (YP125R) 8. Install: • V-belt case air filter element • V-belt case air duct FI Diagnostic Tool • V-belt case cover DIAG V-belt case air duct bolt 7 Nm (0.7 m·kgf, 5.1 ft·lbf) V-belt case cover bolt 7 Nm (0.7 m·kgf, 5.1 ft·lbf) 9.

  • Page 136: Adjusting The Throttle Cable Free Play

    ENGINE (YP125R) 15.Install: EWA12910 WARNING • Upper panel After adjusting the throttle cable free play, Refer to “GENERAL CHASSIS” on page 4-1. start the engine and turn the handlebar to the EAS37P1090 right and to the left to ensure that this does ADJUSTING THE THROTTLE CABLE FREE not cause the engine idling speed to change.

  • Page 137: Checking The Ignition Timing

    ENGINE (YP125R) 7. Install: 4. Check: • Spark plug • Ignition timing M MMM M MMM M MMM M MMM M MMM Spark plug a. Start the engine, warm it up for several min- 13 Nm (1.3 m·kgf, 9.4 ft·lbf) utes, and then let it run at the specified en- gine idling speed.

  • Page 138: Measuring The Compression Pressure

    ENGINE (YP125R) EAS37P1093 MEASURING THE COMPRESSION Standard compression pressure PRESSURE (at sea level) 550 kPa/680 r/min (5.5 kgf/cm²/680 r/min, 78.2 psi/680 Insufficient compression pressure will result in a r/min) loss of performance. Minimum–maximum 1. Remove: 480–620 kPa (4.8–6.2 kgf/cm², 68.3–88.2 psi) •...

  • Page 139: Checking The Engine Oil Level

    ENGINE (YP125R) EAS37P1134 CHECKING THE ENGINE OIL LEVEL 1. Stand the vehicle on a level surface. • Place the vehicle on the centerstand. • Make sure the vehicle is upright. 2. Start the engine, warm it up for several min- utes, and then turn it off.
  • Page 140 ENGINE (YP125R) 5. If the oil filter element is also to be replaced, c. Install the oil strainer cover. perform the following procedure. Oil strainer cover M MMM M MMM M MMM M MMM M MMM 32 Nm (3.2 m·kgf, 23 ft·lbf) a.

  • Page 141: Changing The Final Transmission Oil

    Check the engine oil passages and the oil 4. Remove: pump for damage or leakage. Refer to “OIL • Oil filler cap “1” PUMP (YP125R)” on page 5-48. • O-ring “2” d. Start the engine after solving the problem(s) and check the engine oil pressure again.

  • Page 142: Replacing The Air Filter Element

    ENGINE (YP125R) 9. Start the engine, warm it up for several min- EAS37P1097 CLEANING THE V-BELT CASE AIR FILTER utes, turn it off, and then check for oil leak- ELEMENT age. 1. Remove: • V-belt case cover “1” EAS37P1096 REPLACING THE AIR FILTER ELEMENT •...

  • Page 143: Checking The Throttle Body Joint

    ENGINE (YP125R) EAS37P1099 CHECKING THE FUEL HOSE 1. Remove: • Storage box Refer to “GENERAL CHASSIS” on page 4-1. 2. Check: • Fuel hose “1” Cracks/damage → Replace the fuel injector assembly. Loose connection → Connect properly. 3. Check: • V-belt case air filter element Damage →...

  • Page 144: Checking The Exhaust System

    ENGINE (YP125R) 3. Install: • Storage box Refer to “GENERAL CHASSIS” on page 4-1. EAS37P1101 CHECKING THE EXHAUST SYSTEM 1. Check: • Exhaust pipe “1” • Muffler “2” Cracks/damage → Replace. • Exhaust system connection Exhaust gas leaks → Replace the gaskets EAS37P1102 “3”.

  • Page 145: Checking The Cooling System

    • Radiator filler hose “4” • Coolant reservoir hose “5” • Thermostat cover “6” • Thermostat inlet hose “7” Cracks/damage → Replace. Refer to “RADIATOR (YP125R)” on page 6-1 4. Drain: and “THERMOSTAT (YP125R)” on page 6-3. • Coolant (from the coolant reservoir) 5.
  • Page 146 ENGINE (YP125R) The specified amount of coolant is a standard amount. Fill the cooling system with coolant until coolant comes out of the air bleed bolt hole “1”. 6. Remove: • Coolant drain bolt (from the cylinder) “1” (along with the copper washer)
  • Page 147 ENGINE (YP125R) 13.Install: • Coolant reservoir cap 14.Start the engine, warm it up for several min- utes, and then turn it off. 15.Check: • Coolant level Refer to “CHECKING THE COOLANT LEV- EL” on page 3-17. Before checking the coolant level, wait a few minutes until the coolant has settled.

  • Page 148: Engine (Yp250R)

    ENGINE (YP250R) EAS20470 ENGINE (YP250R) EAS20520 ADJUSTING THE VALVE CLEARANCE The following procedure applies to all of the valves. • Valve clearance adjustment should be made on a cold engine, at room temperature. • When the valve clearance is to be measured or 5.
  • Page 149 ENGINE (YP250R) Tappet adjusting tool 90890-01311 Six piece tappet set YM-A5970 d. Measure the valve clearance with a thickness gauge “1”. Out of specification → Adjust. d. Hold the adjusting screw to prevent it from moving and tighten the locknut to specifica- tion.

  • Page 150: Adjusting The Exhaust Gas Volume

    ENGINE (YP250R) 6. Press the “UP” button to select the CO adjust- EAS20600 ADJUSTING THE EXHAUST GAS VOLUME ment mode “CO” or the diagnostic mode “DI- AG”. Be sure to set the CO density level to standard, 7. After selecting “CO”, press the “MODE” but- and then adjust the exhaust gas volume.

  • Page 151: Checking The Spark Plug

    ENGINE (YP250R) Throttle cable free play 3.0–5.0 mm (0.12–0.20 in) 2. Remove: • Spark plug ECA13330 NOTICE 2. Adjust: Before removing the spark plug, blow away • Throttle cable free play any dirt accumulated in the spark plug well M MMM M MMM M MMM M MMM...

  • Page 152: Checking The Ignition Timing

    ENGINE (YP250R) 4. Check: Spark plug • Ignition timing 18 Nm (1.8 m·kgf, 13 ft·lbf) M MMM M MMM M MMM M MMM M MMM a. Start the engine, warm it up for several min- utes, and then let it run at the specified en- gine idling speed.

  • Page 153: Checking The Engine Oil Level

    ENGINE (YP250R) 3. Start the engine, warm it up for several min- c. If the compression pressure is above the utes, and then turn it off. maximum specification, check the cylinder 4. Disconnect: head, valve surfaces and piston crown for •...

  • Page 154: Changing The Engine Oil

    ENGINE (YP250R) EAS20780 CHANGING THE ENGINE OIL • Before checking the engine oil level, wait a few 1. Start the engine, warm it up for several min- minutes until the oil has settled. utes, and then turn it off. • Do not screw the dipstick in when inspecting 2.

  • Page 155: Changing The Final Transmission Oil

    ENGINE (YP250R) c. Check the engine oil passages and the oil Oil strainer cover pump for damage or leakage. Refer to “OIL 32 Nm (3.2 m·kgf, 23 ft·lbf) PUMP (YP250R)” on page 5-108. d. Start the engine after solving the problem(s) L LLL L LLL L LLL...

  • Page 156: Replacing The Air Filter Element

    ENGINE (YP250R) 9. Start the engine, warm it up for several min- utes, turn it off, and then check for oil leak- age. EAS20960 REPLACING THE AIR FILTER ELEMENT Check hoses are located on the bottom of the air filter case. If dust or water or both collects in a hose, remove the clamp from the hose, and then remove the plug to drain the hose.

  • Page 157: Cleaning The V-Belt Case Air Filter Element

    ENGINE (YP250R) EAS20980 CLEANING THE V-BELT CASE AIR FILTER ELEMENT 1. Remove: • V-belt case air filter cover “1” • V-belt case air filter element 3. Install: • Storage box Refer to “GENERAL CHASSIS” on page 4-1. EAS21030 CHECKING THE FUEL HOSE 1.

  • Page 158: Checking The Exhaust System

    ENGINE (YP250R) 3. Install: • Storage box EAS21110 CHECKING THE COOLANT LEVEL Refer to “GENERAL CHASSIS” on page 4-1. 1. Stand the vehicle on a level surface. EAS21080 CHECKING THE EXHAUST SYSTEM • Place the vehicle on the centerstand. 1. Check: •...

  • Page 159: Checking The Cooling System

    ENGINE (YP250R) 3. Start the engine, warm it up for several min- 3. Install: utes, and then turn it off. • Footrest board 4. Check: • Bottom cover • Coolant level • Storage box Refer to “GENERAL CHASSIS” on page 4-1. Before checking the coolant level, wait a few EAS21130 minutes until it settles.
  • Page 160 ENGINE (YP250R) The specified amount of coolant is a standard amount. Fill the cooling system with coolant until coolant comes out of the air bleed bolt hole “1”. 6. Remove: • Coolant drain bolt (water pump) “1” (along with the copper washer) Handling notes for coolant Coolant is potentially harmful and should be handled with special care.
  • Page 161 ENGINE (YP250R) 13.Install: • Coolant reservoir cap 14.Start the engine, warm it up for several min- utes, and then turn it off. 15.Check: • Coolant level Refer to “CHECKING THE COOLANT LEV- EL” on page 3-31. Before checking the coolant level, wait a few minutes until the coolant has settled.

  • Page 162: Chassis

    → Replace the brake pads as a set. Refer to “FRONT BRAKE” on page 4-17. EAS37P1130 CHECKING THE REAR BRAKE PADS (YP125R) The following procedure applies to all of the A. Front brake brake pads. B. Rear brake 1. Operate the brake.

  • Page 163: Checking The Rear Brake Pads (Yp250R)

    • Rear brake pad Wear indicator groove “a” has almost disap- peared → Replace the brake pads as a set. Refer to “REAR BRAKE” on page 4-29. A. YP125R B. YP250R 3. Hold the vehicle upright and apply the rear brake several times.

  • Page 164: Checking And Adjusting The Steering Head

    Place the vehicle on a suitable stand so that the front wheel is elevated. 2. Check: A. Front brake caliper • Steering head B. Rear brake caliper (YP125R) Grasp the bottom of the front fork legs and C. Rear brake caliper (YP250R) gently rock the front fork. 3-37...
  • Page 165 CHASSIS Binding/looseness → Adjust the steering EWA13140 WARNING head. Do not overtighten the lower ring nut. 3. Remove: • Lower handlebar holder Refer to “STEERING HEAD” on page 4-57. Lower ring nut (final tightening torque) 4. Adjust: 22 Nm (2.2 m·kgf, 16 ft·lbf) •...

  • Page 166: Checking The Front Fork

    CHASSIS 5. Install: Spring preload • Lower handlebar holder ECA13590 NOTICE Refer to “STEERING HEAD” on page 4-57. Never go beyond the maximum or minimum EAS21530 adjustment positions. CHECKING THE FRONT FORK 1. Stand the vehicle on a level surface. 1.
  • Page 167 CHASSIS Wear limit (front) 1.6 mm (0.06 in) Wear limit (rear) 1.6 mm (0.06 in) EWA13180 WARNING • The tire pressure should only be checked and regulated when the tire temperature equals the ambient air temperature. • The tire pressure and the suspension must 1.

  • Page 168: Checking The Wheels

    After a tire or wheel has been changed or re- proved by Yamaha is used on this vehicle. placed, always balance the wheel. Front tire EAS21690...

  • Page 169: Lubricating The Centerstand

    CHASSIS EAS21730 LUBRICATING THE CENTERSTAND Lubricate the pivoting point and metal-to-metal moving parts of the centerstand. Recommended lubricant Lithium-soap-based grease 3-42...

  • Page 170: Electrical System

    ELECTRICAL SYSTEM 5. Install: EAS21750 ELECTRICAL SYSTEM • Headlight bulb Secure the new headlight bulb with the head- EAS21760 CHECKING AND CHARGING THE BATTERY light bulb holder. Refer to “ELECTRICAL COMPONENTS” on ECA13690 NOTICE page 8-71. Avoid touching the glass part of the head- EAS21770 light bulb to keep it free from oil, otherwise CHECKING THE FUSES...

  • Page 171: Adjusting The Headlight Beam

    ELECTRICAL SYSTEM 6. Install: c. Install the adjusting screw accessing cap. L LLL L LLL L LLL L LLL L LLL • Headlight bulb ECA13690 NOTICE Avoid touching the glass part of the head- light bulb to keep it free from oil, otherwise the transparency of the glass, the life of the bulb and the luminous flux will be adversely affected.
  • Page 172 ELECTRICAL SYSTEM 3-45...
  • Page 173 REPLACING THE REAR BRAKE PADS (YP250R)........ 4-38 REMOVING THE REAR BRAKE CALIPER ..........4-39 DISASSEMBLING THE REAR BRAKE CALIPER (YP250R only) ..4-39 CHECKING THE REAR BRAKE CALIPER (YP125R) ......4-40 CHECKING THE REAR BRAKE CALIPER (YP250R) ......4-40 ASSEMBLING THE REAR BRAKE CALIPER ........4-41 INSTALLING THE REAR BRAKE CALIPER (YP125R) ......
  • Page 174 HANDLEBAR ....................4-46 REMOVING THE HANDLEBAR.............. 4-48 CHECKING THE HANDLEBAR .............. 4-48 INSTALLING THE HANDLEBAR ............4-48 FRONT FORK....................4-50 REMOVING THE FRONT FORK LEGS..........4-52 DISASSEMBLING THE FRONT FORK LEGS ........4-52 CHECKING THE FRONT FORK LEGS ..........4-53 ASSEMBLING THE FRONT FORK LEGS ..........

  • Page 176: General Chassis

    GENERAL CHASSIS EAS21830 GENERAL CHASSIS Removing the seat and storage box 23 Nm (2.3 m kgf, 17 ft Ibf) • • 23 Nm (2.3 m kgf, 17 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) • •...

  • Page 177: Removing The Storage Box

    GENERAL CHASSIS M MMM M MMM M MMM M MMM M MMM EAS37P1079 REMOVING THE STORAGE BOX a. Fold the tabs on the safety protector so that 1. Remove: the holes in each tab are aligned, and then • Storage box bolts “1” fasten the tabs to the storage box with the quick fastener screws at the locations “a”...
  • Page 178 GENERAL CHASSIS When tightening the mudguard bolts, tighten the center bolt “a” first, and then tighten the side bolts “b”. 3. Install: • Seat Seat nut 10 Nm (1.0 m·kgf, 7.2 ft·lbf) Tighten the seat nuts in the proper tightening se- quence as shown.
  • Page 179 GENERAL CHASSIS Removing the headlight assembly 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) •...
  • Page 180 GENERAL CHASSIS Removing the meter assembly Order Job/Parts to remove Q’ty Remarks Windshield Refer to “Removing the headlight assembly”. Rearview mirror Center handlebar cover Upper handlebar cover Lower handlebar cover Storage compartment molding Meter assembly coupler Disconnect. Meter assembly cover Meter assembly For installation, reverse the removal proce- dure.
  • Page 181 GENERAL CHASSIS Removing the radiator cover Order Job/Parts to remove Q’ty Remarks Refer to “Removing the seat and storage Storage box box”. Front cowling assembly Refer to “Removing the headlight assembly”. Front turn signal light coupler Disconnect. Front upper panel Front turn signal light Footrest board mat Front lower panel...
  • Page 182 GENERAL CHASSIS Removing the storage compartment 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 11 Nm (1.1 m kgf, 8.0 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Radiator cover...
  • Page 183 Cylinder head breather hose Disconnect. Disconnect. Breather hose (air filter case to throttle body) YP250R only Air filter case joint screw clamp YP125R Air filter case joint screw clamp YP250R Air filter case For installation, reverse the removal proce- dure.

  • Page 184: Front Wheel

    FRONT WHEEL EAS21870 FRONT WHEEL Removing the front wheel and brake disc 23 Nm (2.3 m kgf, 17 ft Ibf) • • 70 Nm (7.0 m kgf, 50 ft Ibf) • • 12 Nm (1.2 m kgf, 8.7 ft Ibf) •...
  • Page 185 FRONT WHEEL Disassembling the front wheel Order Job/Parts to remove Q’ty Remarks Oil seal Wheel bearing Spacer For assembly, reverse the disassembly pro- cedure. 4-10...

  • Page 186: Removing The Front Wheel

    FRONT WHEEL EAS21890 EAS21920 REMOVING THE FRONT WHEEL CHECKING THE FRONT WHEEL 1. Stand the vehicle on a level surface. 1. Check: • Wheel axle EWA13120 WARNING Roll the wheel axle on a flat surface. Bends → Replace. Securely support the vehicle so that there is no danger of it falling over.

  • Page 187: Assembling The Front Wheel

    FRONT WHEEL L LLL L LLL L LLL L LLL L LLL EAS21960 ASSEMBLING THE FRONT WHEEL EAS21970 1. Install: ADJUSTING THE FRONT WHEEL STATIC BALANCE • Wheel bearings M MMM M MMM M MMM M MMM M MMM a. Install the new wheel bearing (right side). •...

  • Page 188: Installing The Front Wheel (Front Brake Disc)

    FRONT WHEEL M MMM M MMM M MMM M MMM M MMM a. Turn the front wheel and make sure it stays at each position shown. f. Repeat steps (c) through (e) several times until all the marks come to rest at the same spot.
  • Page 189 FRONT WHEEL 2. Check: Wheel axle • Front brake disc 70 Nm (7.0 m·kgf, 50 ft·lbf) Refer to “CHECKING THE FRONT BRAKE Wheel axle pinch bolt DISC” on page 4-22. 23 Nm (2.3 m·kgf, 17 ft·lbf) 3. Lubricate: • Oil seal lips ECA37P1030 •...

  • Page 190: Rear Wheel

    17 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Refer to “ENGINE REMOVAL (YP125R)” on Muffler page 5-1 and “ENGINE REMOVAL (YP250R)” on page 5-61. Refer to “REAR SHOCK ABSORBER AS- Swingarm SEMBLIES AND SWINGARM” on page 4-61.

  • Page 191: Removing The Rear Wheel

    REAR WHEEL EAS28760 REMOVING THE REAR WHEEL Tighten the brake disc bolts in stages and in a 1. Stand the vehicle on a level surface. crisscross pattern. EWA13120 WARNING Securely support the vehicle so that there is no danger of it falling over. Place the vehicle on the centerstand so that the rear wheel is elevated.

  • Page 192: Front Brake

    FRONT BRAKE EAS22210 FRONT BRAKE Removing the front brake pads 40 Nm (4.0 m kgf, 29 ft Ibf) • • 6 Nm (0.6 m kgf, 4.3 ft Ibf) • • 18 Nm (1.8 m kgf, 13 ft Ibf) • • 3 Nm (0.3 m kgf, 2.2 ft Ibf)
  • Page 193 FRONT BRAKE Removing the front brake master cylinder 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 23 Nm (2.3 m kgf, 17 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Refer to “GENERAL CHASSIS”...
  • Page 194 FRONT BRAKE Disassembling the front brake master cylinder Order Job/Parts to remove Q’ty Remarks Brake master cylinder kit Brake master cylinder body For assembly, reverse the disassembly pro- cedure. 4-19...
  • Page 195 FRONT BRAKE Removing the front brake caliper 40 Nm (4.0 m kgf, 29 ft Ibf) • • 23 Nm (2.3 m kgf, 17 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Drain. Brake fluid Refer to “BLEEDING THE HYDRAULIC BRAKE SYSTEM”...
  • Page 196 FRONT BRAKE Disassembling the front brake caliper 23 Nm (2.3 m kgf, 17 ft Ibf) • • 6 Nm (0.6 m kgf, 4.3 ft Ibf) • • 13 Nm (1.3 m kgf, 9.4 ft Ibf) • • 18 Nm (1.8 m kgf, 13 ft Ibf) •...

  • Page 197: Introduction

    FRONT BRAKE EAS22220 INTRODUCTION EWA14101 WARNING Disc brake components rarely require disas- sembly. Therefore, always follow these pre- ventive measures: • Never disassemble brake components un- less absolutely necessary. • If any connection on the hydraulic brake system is disconnected, the entire brake L LLL L LLL L LLL...

  • Page 198: Replacing The Front Brake Pads

    FRONT BRAKE d. Measure the brake disc deflection. M MMM M MMM M MMM M MMM M MMM a. Connect a clear plastic hose “1” tightly to the e. If out of specification, repeat the adjustment bleed screw “2”. Put the other end of the hose steps until the brake disc deflection is within into an open container.

  • Page 199: Removing The Front Brake Caliper

    FRONT BRAKE 5. Check: EWA13550 WARNING • Brake lever operation Soft or spongy feeling → Bleed the brake sys- • Cover the brake caliper piston with a rag. Be careful not to get injured when the pis- tem. ton is expelled from the brake caliper. Refer to “BLEEDING THE HYDRAULIC •...

  • Page 200: Assembling The Front Brake Caliper

    • Use only the designated brake fluid. Other sure safe vehicle operation. Refer to “CABLE brake fluids may cause the rubber seals to ROUTING (YP125R)” on page 2-29 and “CA- deteriorate, causing leakage and poor BLE ROUTING (YP250R)” on page 2-75.

  • Page 201: Removing The Front Brake Master Cylinder

    FRONT BRAKE • When refilling, be careful that water does not enter the brake master cylinder reser- To collect any remaining brake fluid, place a voir. Water will significantly lower the boil- container under the master cylinder and the end ing point of the brake fluid and could cause of the brake hose.

  • Page 202: Installing The Front Brake Master Cylinder

    Proper brake hose routing is essential to in- NOTICE sure safe vehicle operation. Refer to “CABLE Brake fluid may damage painted surfaces ROUTING (YP125R)” on page 2-29 and “CA- and plastic parts. Therefore, always clean up BLE ROUTING (YP250R)” on page 2-75. any spilt brake fluid immediately.
  • Page 203 FRONT BRAKE 6. Check: • Brake lever operation Soft or spongy feeling → Bleed the brake sys- tem. Refer to “BLEEDING THE HYDRAULIC BRAKE SYSTEM” on page 3-36. 4-28...

  • Page 204: Rear Brake

    REAR BRAKE EAS22550 REAR BRAKE Removing the rear brake pads (YP125R) 14 Nm (1.4 m kgf, 10 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 40 Nm (4.0 m kgf, 29 ft Ibf) •...
  • Page 205 REAR BRAKE Removing the rear brake pads (YP250R) 6 Nm (0.6 m kgf, 4.3 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 27 Nm (2.7 m kgf, 19 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Rear brake caliper retaining bolt...
  • Page 206 REAR BRAKE Removing the rear brake master cylinder 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 23 Nm (2.3 m kgf, 17 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Refer to “GENERAL CHASSIS”...
  • Page 207 REAR BRAKE Disassembling the rear brake master cylinder Order Job/Parts to remove Q’ty Remarks Brake master cylinder kit Brake master cylinder body For assembly, reverse the disassembly pro- cedure. 4-32...
  • Page 208 REAR BRAKE Removing the rear brake caliper (YP125R) 28 Nm (2.8 m kgf, 20 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 40 Nm (4.0 m kgf, 29 ft Ibf) • • Order Job/Parts to remove Q’ty...
  • Page 209 REAR BRAKE Removing the rear brake caliper (YP250R) 23 Nm (2.3 m kgf, 17 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 40 Nm (4.0 m kgf, 29 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Refer to “ENGINE REMOVAL (YP250R)”...
  • Page 210 REAR BRAKE Disassembling the rear brake caliper (YP125R) 14 Nm (1.4 m kgf, 10 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Brake pad clip Brake pad pin Rear brake pad Brake pad spring Bleed screw/cap For assembly, reverse the disassembly pro- cedure.
  • Page 211 REAR BRAKE Disassembling the rear brake caliper (YP250R) 6 Nm (0.6 m kgf, 4.3 ft Ibf) • • 27 Nm (2.7 m kgf, 19 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Rear brake caliper retaining bolt Brake caliper bracket Rear brake pad Brake pad shim Brake pad support...

  • Page 212: Introduction

    Refer to “CHECKING THE FRONT BRAKE DISC” on page 4-22. Brake disc deflection limit 0.25 mm (0.0098 in) (YP125R) 0.15 mm (0.0059 in) (YP250R) 4. Measure: • Brake disc thickness Measure the brake disc thickness at a few dif- 2.

  • Page 213: Replacing The Rear Brake Pads (Yp250R)

    REAR BRAKE 5. Check: • Brake lever operation Always install new brake pads and a new brake Soft or spongy feeling → Bleed the brake sys- pad spring as a set. tem. M MMM M MMM M MMM M MMM M MMM Refer to “BLEEDING THE HYDRAULIC a.

  • Page 214: Removing The Rear Brake Caliper

    27 Nm (2.7 m·kgf, 19 ft·lbf) 4. Check: • Brake fluid level Below the minimum level mark “a” → Add the recommended brake fluid to the proper level. A. YP125R Refer to “CHECKING THE BRAKE FLUID B. YP250R LEVEL” on page 3-35. EAS22610...

  • Page 215: Checking The Rear Brake Caliper (Yp125R)

    L LLL L LLL 1. Check: EAS37P1132 CHECKING THE REAR BRAKE CALIPER • Brake caliper pistons “1” (YP125R) Rust/scratches/wear → Replace the brake Recommended brake component replace- caliper pistons. ment schedule • Brake caliper cylinders “2” Scratches/wear → Replace the brake caliper...

  • Page 216: Assembling The Rear Brake Caliper

    1. Install: 40 Nm (4.0 m·kgf, 29 ft·lbf) • Rear brake caliper “1” (temporarily) Refer to “REPLACING THE REAR BRAKE PADS (YP125R)” on page 4-37. • Copper washers “2” 4. Fill: • Rear brake hose “3” • Brake master cylinder reservoir •...

  • Page 217: Installing The Rear Brake Caliper (Yp250R)

    REAR BRAKE ECA13540 NOTICE Brake fluid may damage painted surfaces and plastic parts. Therefore, always clean up any spilt brake fluid immediately. 5. Bleed: • Brake system Refer to “BLEEDING THE HYDRAULIC BRAKE SYSTEM” on page 3-36. 6. Check: EWA13530 •...

  • Page 218: Removing The Rear Brake Master Cylinder

    REAR BRAKE EWA13540 EAS22700 REMOVING THE REAR BRAKE MASTER WARNING CYLINDER • Use only the designated brake fluid. Other brake fluids may cause the rubber seals to deteriorate, causing leakage and poor Before removing the rear brake master cylinder, brake performance. drain the brake fluid from the entire brake sys- tem.

  • Page 219: Assembling The Rear Brake Master Cylinder

    Proper brake hose routing is essential to in- any spilt brake fluid immediately. sure safe vehicle operation. Refer to “CABLE 4. Bleed: ROUTING (YP125R)” on page 2-29 and “CA- • Brake system BLE ROUTING (YP250R)” on page 2-75. Refer to “BLEEDING THE HYDRAULIC BRAKE SYSTEM”...
  • Page 220 REAR BRAKE 5. Check: • Brake fluid level Below the minimum level mark “a” → Add the recommended brake fluid to the proper level. Refer to “CHECKING THE BRAKE FLUID LEVEL” on page 3-35. 6. Check: • Brake lever operation Soft or spongy feeling →...

  • Page 221: Handlebar

    HANDLEBAR EAS22840 HANDLEBAR Removing the handlebar 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 23 Nm (2.3 m kgf, 17 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 26 Nm (2.6 m kgf, 19 ft Ibf) •...
  • Page 222 HANDLEBAR Removing the handlebar 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 23 Nm (2.3 m kgf, 17 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 26 Nm (2.6 m kgf, 19 ft Ibf) •...

  • Page 223: Removing The Handlebar

    HANDLEBAR EAS22860 REMOVING THE HANDLEBAR The upper handlebar holders should be installed 1. Stand the vehicle on a level surface. with the arrow marks “a” facing forward “A”. EWA13120 WARNING Securely support the vehicle so that there is no danger of it falling over. 2.
  • Page 224 HANDLEBAR • Align the projection “a” on the brake master cyl- inder with the hole “b” in the handlebar. • First, tighten the front bolt, then the rear bolt. 8. Adjust: • Throttle cable free play Refer to “ADJUSTING THE THROTTLE CA- BLE FREE PLAY”...

  • Page 225: Front Fork

    FRONT FORK EAS22950 FRONT FORK Removing the front fork legs 45 Nm (4.5 m kgf, 32 ft Ibf) • • 23 Nm (2.3 m kgf, 17 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf)
  • Page 226 FRONT FORK Disassembling the front fork legs 30 Nm (3.0 m kgf, 22 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks The following procedure applies to both of the front fork legs. Fork spring Dust seal Oil seal clip Damper rod bolt Copper washer Damper rod...

  • Page 227: Removing The Front Fork Legs

    FRONT FORK EAS22960 REMOVING THE FRONT FORK LEGS The following procedure applies to both of the front fork legs. 1. Stand the vehicle on a level surface. EWA13120 WARNING Securely support the vehicle so that there is no danger of it falling over. 2.

  • Page 228: Checking The Front Fork Legs

    FRONT FORK EAS23030 ASSEMBLING THE FRONT FORK LEGS The following procedure applies to both of the front fork legs. EWA13660 WARNING • Make sure the oil levels in both front fork legs are equal. • Uneven oil levels can result in poor han- dling and a loss of stability.
  • Page 229 FRONT FORK While holding the damper rod with the damper rod holder “2” and T-handle “3”, tighten the damper rod bolt. Damper rod holder 90890-01294 Damping rod holder set YM-01300 T-handle 90890-01326 T-handle 3/8" drive 60 cm long YM-01326 5. Install: •...

  • Page 230: Installing The Front Fork Legs

    FRONT FORK 10.Measure: • Front fork leg oil level “a” (from the top of the inner tube, with the inner tube fully compressed and without the fork spring) Out of specification → Correct. Level 109.0 mm (4.29 in) 7. Fill: •...
  • Page 231 FRONT FORK 2. Install: • Cap bolt (along with the O-ring Cap bolt 45 Nm (4.5 m·kgf, 32 ft·lbf) ECA37P1028 NOTICE When installing the cap bolt, take care not to damage the rectifier/regulator with the tools. • Before installing the cap bolt, lubricate its O- ring with grease.

  • Page 232: Steering Head

    STEERING HEAD EAS23090 STEERING HEAD Removing the lower bracket 120 Nm (12.0 m kgf, 85 ft lbf) • • 75 Nm (7.5 m kgf, 54 ft Ibf) • • 1st 38 Nm (3.8 m kgf, 27 ft lbf) • • 2nd 22 Nm (2.2 m kgf, 16 ft lbf)
  • Page 233 STEERING HEAD Removing the lower bracket 120 Nm (12.0 m kgf, 85 ft lbf) • • 75 Nm (7.5 m kgf, 54 ft Ibf) • • 1st 38 Nm (3.8 m kgf, 27 ft lbf) • • 2nd 22 Nm (2.2 m kgf, 16 ft lbf) •...

  • Page 234: Removing The Lower Bracket

    STEERING HEAD M MMM M MMM M MMM M MMM M MMM EAS23110 REMOVING THE LOWER BRACKET a. Remove the bearing races from the steering 1. Stand the vehicle on a level surface. head pipe “1” with a long rod “2” and hammer. EWA13120 b.
  • Page 235 STEERING HEAD • Rubber washer • Center ring nut “2” • Lock washer “3” • Upper ring nut “4” Refer to “CHECKING AND ADJUSTING THE STEERING HEAD” on page 3-37. 3. Install: • Woodruff key “1” • Lower handlebar holder “2” •...

  • Page 236: Rear Shock Absorber Assemblies And Swingarm

    REAR SHOCK ABSORBER ASSEMBLIES AND SWINGARM EAS23160 REAR SHOCK ABSORBER ASSEMBLIES AND SWINGARM Removing the rear shock absorber assemblies and swingarm (YP125R) 135 Nm (13.5 m kgf, 98 ft lbf) • • 40 Nm (4.0 m kgf, 29 ft Ibf) •...
  • Page 237 REAR SHOCK ABSORBER ASSEMBLIES AND SWINGARM Removing the rear shock absorber assemblies and swingarm (YP250R) 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 135 Nm (13.5 m kgf, 98 ft lbf) • • 18 Nm (1.8 m kgf, 13 ft Ibf) 40 Nm (4.0 m kgf, 29 ft...

  • Page 238: Removing The Rear Shock Absorber Assemblies

    • Swingarm mounting bolt (upper side) “3” (temporarily tighten) • Swingarm mounting bolt (lower side) “4” (temporarily tighten) 3. Tighten: • Rear wheel axle nut “2” • Swingarm mounting bolt (upper side) “3” • Swingarm mounting bolt (lower side) “4” A. YP125R B. YP250R 4-63...
  • Page 239 Swingarm mounting bolt (upper side) 28 Nm (2.8 m·kgf, 20 ft·lbf) (YP125R) 59 Nm (5.9 m·kgf, 43 ft·lbf) (YP250R) Swingarm mounting bolt (lower side) 28 Nm (2.8 m·kgf, 20 ft·lbf) (YP125R) 59 Nm (5.9 m·kgf, 43 ft·lbf) (YP250R) A. YP125R B. YP250R 4-64...
  • Page 240 REAR SHOCK ABSORBER ASSEMBLIES AND SWINGARM 4-65...
  • Page 241 CHECKING THE DECOMPRESSION SYSTEM........5-15 CHECKING THE ROCKER ARMS AND ROCKER ARM SHAFTS ..5-16 INSTALLING THE CAMSHAFT AND ROCKER ARMS ......5-17 VALVES AND VALVE SPRINGS (YP125R) ..........5-18 REMOVING THE VALVES..............5-19 CHECKING THE VALVES AND VALVE GUIDES ........5-19 CHECKING THE VALVE SEATS ............
  • Page 242 STARTER CLUTCH AND GENERATOR (YP125R)........5-39 REMOVING THE GENERATOR ............. 5-41 REMOVING THE STARTER CLUTCH ........... 5-41 CHECKING THE STARTER CLUTCH ............ 5-41 INSTALLING THE STARTER CLUTCH ..........5-42 INSTALLING THE GENERATOR............5-42 ELECTRIC STARTER (YP125R) ..............5-44 CHECKING THE STARTER MOTOR ............. 5-46 OIL PUMP (YP125R) ..................
  • Page 243 VALVES AND VALVE SPRINGS (YP250R) ..........5-77 REMOVING THE VALVES..............5-78 CHECKING THE VALVES AND VALVE GUIDES ........5-78 CHECKING THE VALVE SEATS ............5-80 CHECKING THE VALVE SPRINGS............5-81 INSTALLING THE VALVES ..............5-82 CYLINDER AND PISTON (YP250R)............. 5-84 REMOVING THE PISTON ..............
  • Page 244 CRANKSHAFT (YP250R) ................5-115 DISASSEMBLING THE CRANKCASE..........5-117 REMOVING THE CRANKSHAFT ASSEMBLY ........5-117 CHECKING THE TIMING CHAIN AND TIMING CHAIN GUIDE... 5-118 CHECKING THE CRANKSHAFT AND CONNECTING ROD ....5-118 CHECKING THE CRANKCASE ............5-119 CHECKING THE BEARING AND OIL SEAL.........5-119 CHECKING THE OIL STRAINERS ............5-119 INSTALLING THE CRANKSHAFT ............5-119 ASSEMBLING THE CRANKCASE............5-120...

  • Page 246: Engine Removal (Yp125R)

    ENGINE REMOVAL (YP125R) EAS37P1135 ENGINE REMOVAL (YP125R) Removing the muffler and exhaust pipe 45 Nm (4.5 m kgf, 32 ft Ibf) • • 53 Nm (5.3 m kgf, 38 ft Ibf) • • 20 Nm (2.0 m kgf, 14 ft Ibf) 14 Nm (1.4 m...
  • Page 247 Refer to “GENERAL CHASSIS” on page Air filter case 4-1. Refer to “V-BELT AUTOMATIC TRANSMIS- V-belt case air duct joint SION (YP125R)” on page 5-30. Fuel injector assembly/Throttle body/Intake Refer to “THROTTLE BODY” on page 7-5. manifold Spark plug cap Disconnect.
  • Page 248 ENGINE REMOVAL (YP125R) Disconnecting the leads and hoses 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Ground lead Disconnect. For installation, reverse the removal proce- dure.
  • Page 249 ENGINE REMOVAL (YP125R) Removing the engine 59 Nm (5.9 m kgf, 43 ft Ibf) • • 32 Nm (3.2 m kgf, 23 ft Ibf) • • 43 Nm (4.3 m kgf, 31 ft Ibf) • • 18 Nm (1.8 m...

  • Page 250: Installing The Engine

    ENGINE REMOVAL (YP125R) EAS37P1136 INSTALLING THE ENGINE 1. Install: • Engine “1” • Engine bracket “2” • Engine bracket rods “3” • Spacer “4” • Engine mounting nut/washer/bolt “5” • Engine bracket rod bolts/washers/nuts “6” • Engine bracket nuts/bolts “7”...
  • Page 251 ENGINE REMOVAL (YP125R) Tighten the muffler mounting bolts in the proper tightening sequence as shown. 7. Tighten: • Exhaust pipe nuts Exhaust pipe nut 20 Nm (2.0 m·kgf, 14 ft·lbf) 8. Tighten: • Muffler joint bolt • O sensor Muffler joint bolt 14 Nm (1.4 m·kgf, 10 ft·lbf)

  • Page 252: Engine

    • Order Job/Parts to remove Q’ty Remarks Refer to “THERMOSTAT (YP125R)” on page Thermostat 6-3. Refer to “WATER PUMP (YP125R)” on page Water pump 6-5. Refer to “ENGINE REMOVAL (YP125R)” on Engine page 5-1. Timing mark accessing plug Spark plug...
  • Page 253 CYLINDER HEAD (YP125R) Removing the cylinder head 10 Nm (1.0 m kgf, 7.2 ft Ibf) 8 Nm (0.8 m kgf, 5.8 ft Ibf) 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • • • • • 13 Nm (1.3 m kgf, 9.4 ft...

  • Page 254: Removing The Cylinder Head

    CYLINDER HEAD (YP125R) EAS37P1002 REMOVING THE CYLINDER HEAD 1. Align: • “I” mark “a” on the generator rotor (with the stationary pointer “b” on the genera- tor cover) M MMM M MMM M MMM M MMM M MMM a. Turn the primary sheave nut on the left side of the crankshaft counterclockwise to turn the crankshaft.

  • Page 255: Checking The Camshaft Sprocket

    CYLINDER HEAD (YP125R) c. If the limit is exceeded, resurface the cylinder head as follows. Do not use a sharp instrument to avoid damag- d. Place 400–600 grit wet sandpaper on the sur- ing or scratching: face plate and resurface the cylinder head •...

  • Page 256: Installing The Cylinder Head

    CYLINDER HEAD (YP125R) b. Align the “I” mark “a” on the generator rotor with the stationary pointer “b” on the genera- tor cover. c. Install the timing chain “1” onto the camshaft sprocket “2”, then the camshaft sprocket onto the camshaft, and then finger tighten the camshaft sprocket bolt.
  • Page 257 CYLINDER HEAD (YP125R) Timing chain tensioner bolt 10 Nm (1.0 m·kgf, 7.2 ft·lbf) d. Turn the timing chain tensioner rod counter- clockwise with a thin screwdriver “1”, make sure it releases, and then install the timing chain tensioner plug. e. While holding the primary sheave nut with a wrench, temporarily tighten the camshaft sprocket bolt.
  • Page 258 CYLINDER HEAD (YP125R) 6. Tighten: • Camshaft sprocket bolt Camshaft sprocket bolt 30 Nm (3.0 m·kgf, 22 ft·lbf) ECA37P1002 NOTICE Be sure to tighten the camshaft sprocket bolt to the specified torque to avoid the possibil- ity of the bolt coming loose and damaging the engine.

  • Page 259: Camshaft (Yp125R)

    7 Nm (0.7 m kgf, 5.1 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Refer to “CYLINDER HEAD (YP125R)” on Cylinder head page 5-7. Locknut Adjusting screw Decompression cam Camshaft retainer Camshaft Rocker arm shaft Intake rocker arm...

  • Page 260: Removing The Camshaft

    CAMSHAFT (YP125R) EAS37P1008 REMOVING THE CAMSHAFT 1. Remove: • Camshaft “1” Screw an M8 bolt “2” into the threaded end of the camshaft, and then pull out the camshaft. EAS37P1009 CHECKING THE CAMSHAFT 1. Check: 3. Check: • Camshaft lobes Blue discoloration/pitting/scratches →...

  • Page 261: Checking The Rocker Arms And Rocker Arm Shafts

    CAMSHAFT (YP125R) Rocker arm inside diameter 9.985–10.000 mm (0.3931– 0.3937 in) Limit 10.015 mm (0.3943 in) 4. Measure: • Rocker arm shaft outside diameter “a” Out of specification → Replace. Rocker arm shaft outside diame- L LLL L LLL L LLL...

  • Page 262: Installing The Camshaft And Rocker Arms

    CAMSHAFT (YP125R) EAS37P1012 INSTALLING THE CAMSHAFT AND ROCKER ARMS 1. Lubricate: • Camshaft Recommended lubricant Camshaft Molybdenum disulfide grease Camshaft bearing Engine oil 5. Install: 2. Lubricate: • Camshaft retainer • Rocker arms Camshaft retainer bolt • Rocker arm shafts 7 Nm (0.7 m·kgf, 5.1 ft·lbf)

  • Page 263: Valves And Valve Springs (Yp125R)

    EAS37P1013 VALVES AND VALVE SPRINGS (YP125R) Removing the valves and valve springs Order Job/Parts to remove Q’ty Remarks Refer to “CYLINDER HEAD (YP125R)” on Cylinder head page 5-7. Refer to “CAMSHAFT (YP125R)” on page Rocker arms/Camshaft 5-14. Valve cotter Upper spring seat...

  • Page 264: Removing The Valves

    VALVES AND VALVE SPRINGS (YP125R) EAS37P1014 REMOVING THE VALVES The following procedure applies to all of the valves and related components. Before removing the internal parts of the cylinder head (e.g., valves, valve springs, valve seats), make sure the valves properly seal.
  • Page 265 VALVES AND VALVE SPRINGS (YP125R) b. Install the new valve guide with the valve Valve-stem-to-valve-guide clear- guide installer “2” and valve guide remover ance (intake) “1”. 0.010–0.037 mm (0.0004–0.0015 Valve guide position Limit Intake 0.080 mm (0.0031 in) 17.0–17.4 mm (0.670–0.685 in)

  • Page 266: Checking The Valve Seats

    VALVES AND VALVE SPRINGS (YP125R) 3. Eliminate: EAS37P1016 CHECKING THE VALVE SEATS • Carbon deposits The following procedure applies to all of the (from the valve face and valve seat) valves and valve seats. 4. Check: 1. Eliminate: • Valve face •...

  • Page 267: Checking The Valve Springs

    VALVES AND VALVE SPRINGS (YP125R) e. Apply a fine lapping compound to the valve face and repeat the above steps. Where the valve seat and valve face contacted f. After every lapping procedure, be sure to one another, the blueing will have been re- clean off all of the lapping compound from the moved.

  • Page 268: Installing The Valves

    VALVES AND VALVE SPRINGS (YP125R) 2. Measure: 1. Deburr: • Compressed valve spring force “a” • Valve stem end Out of specification → Replace the valve (with an oil stone) spring. Installed compression spring force (intake) 140–162 N (14.28–16.52 kgf, 31.47–36.42 lbf)
  • Page 269 VALVES AND VALVE SPRINGS (YP125R) b. Smaller pitch 4. Install: • Valve cotters “1” Install the valve cotters by compressing the valve spring with the valve spring compressor and the valve spring compressor attachment “2”. Valve spring compressor 90890-04019 YM-04019...

  • Page 270: Cylinder And Piston (Yp125R)

    7 Nm (0.7 m kgf, 5.1 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Refer to “CYLINDER HEAD (YP125R)” on Cylinder head page 5-7. Timing chain guide (exhaust side) Cylinder Cylinder gasket Dowel pin Clip Piston pin Piston...

  • Page 271: Removing The Piston

    CYLINDER AND PISTON (YP125R) EAS37P1020 REMOVING THE PISTON When removing a piston ring, open the end gap 1. Remove: with your fingers and lift the other side of the ring • Piston pin clips “1” over the piston crown. • Piston pin “2”...

  • Page 272: Checking The Piston Rings

    CYLINDER AND PISTON (YP125R) EAS37P1081 CHECKING THE PISTON RINGS 1. Measure: • Piston ring side clearance Out of specification → Replace the piston and piston rings as a set. Before measuring the piston ring side clearance, eliminate any carbon deposits from the piston ring grooves and piston rings.

  • Page 273: Checking The Piston Pin

    CYLINDER AND PISTON (YP125R) 3. Measure: 3. Measure: • Piston ring end gap • Piston pin bore diameter “b” Out of specification → Replace the piston Out of specification → Replace the piston. ring. Piston pin bore inside diameter 14.002–14.013 mm (0.5513–...
  • Page 274 CYLINDER AND PISTON (YP125R) 120˚ 120˚ 120˚ 2. Install: a. Top ring • Piston “1” b. Upper oil ring rail • Piston pin “2” c. Oil ring expander d. Lower oil ring rail • Piston pin clips “3” e. 2nd ring f.

  • Page 275: V-Belt Automatic Transmission (Yp125R)

    V-BELT AUTOMATIC TRANSMISSION (YP125R) EAS37P1137 V-BELT AUTOMATIC TRANSMISSION (YP125R) Removing the V-belt case cover 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) •...
  • Page 276 V-BELT AUTOMATIC TRANSMISSION (YP125R) Removing the V-belt, primary sheave and secondary sheave 55 Nm (5.5 m kgf, 40 ft Ibf) • • 60 Nm (6.0 m kgf, 43 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Primary sheave nut/Washer...
  • Page 277 V-BELT AUTOMATIC TRANSMISSION (YP125R) Disassembling the secondary sheave 90 Nm (9.0 m kgf, 65 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Clutch carrier nut Clutch carrier Clip Clutch carrier plate Clutch shoe spring Compression spring Spring seat...

  • Page 278: Removing The Primary Sheave

    V-BELT AUTOMATIC TRANSMISSION (YP125R) EAS37P1025 REMOVING THE PRIMARY SHEAVE 1. Remove: • V-belt case Loosen each bolt 1/4 of a turn at a time, in stag- es and in a crisscross pattern. After all of the bolts are fully loosened, remove them.

  • Page 279: Disassembling The Secondary Sheave

    V-BELT AUTOMATIC TRANSMISSION (YP125R) EAS37P1027 EAS37P1029 DISASSEMBLING THE SECONDARY CHECKING THE CLUTCH SHOES The following procedure applies to all of the SHEAVE 1. Remove: clutch shoes. • Clutch carrier nut “1” 1. Check: • Clutch shoe Damage/wear → Replace the clutch shoes While compressing the compression spring with and springs as a set.

  • Page 280: Checking The Primary Sheave

    V-BELT AUTOMATIC TRANSMISSION (YP125R) EAS37P1033 CHECKING THE PRIMARY SHEAVE V-belt width SLIDERS 22.0 mm (0.87 in) 1. Check: Limit 19.8 mm (0.78 in) • Primary sheave slider Cracks/damage/wear → Replace. EAS37P1034 CHECKING THE SECONDARY SHEAVE 1. Check: • Secondary fixed sheave •...

  • Page 281: Assembling The Secondary Sheave

    V-BELT AUTOMATIC TRANSMISSION (YP125R) • Primary sliding sheave 2. Install: • Spacer • Oil seal • Primary sheave weights • Secondary sliding sheave “1” • Cam 2. Lubricate: Install the secondary sliding sheave onto the • Oil seal secondary fixed sheave “2” with the oil seal •...

  • Page 282: Installing The V-Belt

    V-BELT AUTOMATIC TRANSMISSION (YP125R) • Install the clutch carrier nut “2” with its tapered 2. Tighten: side “a” facing the clutch carrier. • Clutch carrier nut “1” Clutch carrier nut Clutch spring holder 90 Nm (9.0 m·kgf, 65 ft·lbf) 90890-01337...
  • Page 283 V-BELT AUTOMATIC TRANSMISSION (YP125R) 4. Install: 6. Install: • V-belt “1” • V-belt case • Primary fixed sheave “2” • Washer • Make sure that the V-belt case gasket lip fits • Primary sheave nut “3” properly around the V-belt case.

  • Page 284: Starter Clutch And Generator (Yp125R)

    Job/Parts to remove Q’ty Remarks Drain. Engine oil Refer to “CHANGING THE ENGINE OIL” on page 3-12. Refer to “ENGINE REMOVAL (YP125R)” on Muffler/Exhaust pipe page 5-1. Crankshaft position sensor coupler/Stator as- Disconnect. sembly coupler Generator cover Generator cover gasket...
  • Page 285 STARTER CLUTCH AND GENERATOR (YP125R) Removing the generator rotor and starter clutch 13 Nm (1.3 m kgf, 9.4 ft Ibf) • • 80 Nm (8.0 m kgf, 58 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Circlip Washer...

  • Page 286: Removing The Generator

    STARTER CLUTCH AND GENERATOR (YP125R) EAS37P1039 REMOVING THE GENERATOR 1. Remove: • Generator cover Loosen each bolt 1/4 of a turn at a time, in stag- es and in a crisscross pattern. After all of the bolts are fully loosened, remove them.

  • Page 287: Installing The Starter Clutch

    STARTER CLUTCH AND GENERATOR (YP125R) • While holding the generator rotor “2” with the sheave holder “3”, tighten the starter clutch bolts. • Do not allow the sheave holder to touch the projection on the generator rotor. Sheave holder 90890-01701 Primary clutch holder 2.
  • Page 288 STARTER CLUTCH AND GENERATOR (YP125R) Sheave holder Generator cover bolt 90890-01701 10 Nm (1.0 m·kgf, 7.2 ft·lbf) Primary clutch holder YS-01880-A Tighten the generator cover bolts in stages and in a crisscross pattern. 3. Apply: • Sealant (onto the crankshaft position sensor/stator assembly lead grommet) Yamaha bond No.

  • Page 289: Electric Starter (Yp125R)

    ELECTRIC STARTER (YP125R) EAS37P1044 ELECTRIC STARTER (YP125R) Removing the starter motor 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Refer to “GENERAL CHASSIS” on page Storage box/Air filter case 4-1. Starter motor lead Disconnect.
  • Page 290 ELECTRIC STARTER (YP125R) Disassembling the starter motor Order Job/Parts to remove Q’ty Remarks O-ring Starter motor yoke O-ring Armature assembly Shim Brush Spring Front bracket/brush holder set For assembly, reverse the disassembly pro- cedure. 5-45...

  • Page 291: Checking The Starter Motor

    ELECTRIC STARTER (YP125R) EAS37P1045 CHECKING THE STARTER MOTOR Digital circuit tester 1. Check: 90890-03174 • Commutator Model 88 Multimeter with ta- Dirt → Clean with 600 grit sandpaper. chometer YU-A1927 2. Measure: • Commutator diameter “a” Out of specification → Replace the starter Armature coil motor.
  • Page 292 ELECTRIC STARTER (YP125R) 7. Check: • Gear teeth Damage/wear → Replace the gear. 8. Check: • Bearing • Oil seal • Bushing Damage/wear → Replace the defective part(s). 5-47...
  • Page 293 Order Job/Parts to remove Q’ty Remarks Refer to “STARTER CLUTCH AND GENER- Starter clutch gear ATOR (YP125R)” on page 5-39. Oil pump plate Oil pump assembly Oil pump housing cover Oil pump driven gear Oil pump inner rotor Oil pump outer rotor...

  • Page 294: Oil Pump (Yp125R)

    OIL PUMP (YP125R) EAS37P1047 CHECKING THE OIL PUMP Inner-rotor-to-outer-rotor-tip 1. Check: clearance • Oil pump drive gear Less than 0.15 mm (0.0059 in) • Oil pump driven gear Limit 0.23 mm (0.0091 in) • Oil pump housing Outer-rotor-to-oil-pump-housing • Oil pump housing cover clearance Cracks/damage/wear →...

  • Page 295: Installing The Oil Pump

    OIL PUMP (YP125R) When installing the inner rotor, align the pin “4” in the oil pump driven gear with the groove “a” in the inner rotor. 4. Check: • Oil pump operation Refer to “CHECKING THE OIL PUMP” on page 5-49.
  • Page 296 Drain. Final transmission oil Refer to “CHANGING THE FINAL TRANS- MISSION OIL” on page 3-14. Refer to “V-BELT AUTOMATIC TRANSMIS- Secondary sheave assembly SION (YP125R)” on page 5-30. Transmission case cover Gasket Dowel pin Primary drive gear Washer Conical spring washer...

  • Page 297: Transmission (Yp125R)

    TRANSMISSION (YP125R) Removing the transmission 16 Nm (1.6 m kgf, 11 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Drive axle For installation, reverse the removal proce- dure. 5-52...

  • Page 298: Removing The Transmission

    TRANSMISSION (YP125R) EAS37P1051 REMOVING THE TRANSMISSION 1. Remove: • Transmission case cover Loosen each bolt 1/4 of a turn at a time, in stag- es and in a crisscross pattern. After all of the bolts are fully loosened, remove them.

  • Page 299: Crankshaft (Yp125R)

    Refer to “CYLINDER AND PISTON Piston (YP125R)” on page 5-25. Refer to “V-BELT AUTOMATIC TRANSMIS- Belt drive SION (YP125R)” on page 5-30. Refer to “OIL PUMP (YP125R)” on page Oil pump assembly 5-48. Refer to “TRANSMISSION (YP125R)” on Transmission page 5-51.
  • Page 300 CRANKSHAFT (YP125R) Removing the crankshaft 20 Nm (2.0 m kgf, 14 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 32 Nm (3.2 m kgf, 23 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) •...

  • Page 301: Disassembling The Crankcase

    CRANKSHAFT (YP125R) EAS37P1055 ECA37P1008 DISASSEMBLING THE CRANKCASE NOTICE 1. Remove: • To protect the end of the crankshaft, place • Crankcase bolts an appropriate sized socket “4” between the crankcase separating tool bolt and the Loosen each bolt 1/4 of a turn at a time, in stag- crankshaft.

  • Page 302: Checking The Crankcase

    CRANKSHAFT (YP125R) • Bearing “2” Runout limit C Cracks/damage/wear → Replace the crank- 0.030 mm (0.0012 in) shaft. 5. Check: 2. Measure: • Crankshaft journal • Big end side clearance Scratches/wear → Replace the crankshaft. Out of specification → Replace the crank- •...

  • Page 303: Checking The Oil Strainers

    CRANKSHAFT (YP125R) EAS37P1062 CHECKING THE OIL STRAINERS Crankshaft installer pot 1. Check: 90890-01274 • Oil strainers Installing pot Damage → Replace. YU-90058 Contaminants → Clean with solvent. Crankshaft installer bolt 90890-01275 Bolt EAS37P1063 INSTALLING THE CRANKSHAFT YU-90060 1. Lubricate: Adapter (M14) •...

  • Page 304: Assembling The Crankcase

    • M6 × 70 mm (2.76 in) bolts: “3” 2. Apply: • Sealant (onto the crankcase mating surfaces) Yamaha bond No. 1215 90890-85505 (Three Bond No.1215®) Do not allow any sealant to come into contact with the oil gallery.
  • Page 305 CRANKSHAFT (YP125R) 5-60...

  • Page 306: Engine Removal (Yp250R)

    ENGINE REMOVAL (YP250R) EAS23710 ENGINE REMOVAL (YP250R) Removing the muffler and exhaust pipe 45 Nm (4.5 m kgf, 32 ft Ibf) • • 65 Nm (6.5 m kgf, 47 ft Ibf) • • 14 Nm (1.4 m kgf, 10 ft Ibf) •...
  • Page 307 ENGINE REMOVAL (YP250R) Disconnecting the leads and hoses 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Drain. Engine oil Refer to “CHANGING THE ENGINE OIL” on page 3-27. Drain. Coolant Refer to “CHANGING THE COOLANT” on page 3-32.
  • Page 308 ENGINE REMOVAL (YP250R) Disconnecting the leads and hoses 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Ground lead Disconnect. For installation, reverse the removal proce- dure. 5-63...
  • Page 309 ENGINE REMOVAL (YP250R) Removing the engine 59 Nm (5.9 m kgf, 43 ft Ibf) • • 32 Nm (3.2 m kgf, 23 ft Ibf) • • 43 Nm (4.3 m kgf, 31 ft Ibf) • • 18 Nm (1.8 m kgf, 13 ft Ibf) •...

  • Page 310: Installing The Engine

    ENGINE REMOVAL (YP250R) EAS23720 INSTALLING THE ENGINE 1. Install: • Engine “1” • Engine bracket “2” • Engine bracket rods “3” • Spacer “4” • Engine mounting nut/washer/bolt “5” • Engine bracket rod bolts/washers/nuts “6” • Engine bracket nuts/bolts “7” •...
  • Page 311 ENGINE REMOVAL (YP250R) Tighten the muffler mounting bolts in the proper tightening sequence as shown. 7. Tighten: • Exhaust pipe nuts Exhaust pipe nut 20 Nm (2.0 m·kgf, 14 ft·lbf) 8. Tighten: • Muffler joint bolt • O sensor Muffler joint bolt 14 Nm (1.4 m·kgf, 10 ft·lbf) sensor 45 Nm (4.5 m·kgf, 32 ft·lbf)

  • Page 312: Cylinder Head (Yp250R)

    CYLINDER HEAD (YP250R) EAS24100 CYLINDER HEAD (YP250R) Removing the cylinder head 18 Nm (1.8 m kgf, 13 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 60 Nm (6.0 m kgf, 43 ft Ibf) • •...
  • Page 313 CYLINDER HEAD (YP250R) Removing the cylinder head 18 Nm (1.8 m kgf, 13 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 60 Nm (6.0 m kgf, 43 ft Ibf) • • 22 Nm (2.2 m kgf, 16 ft Ibf) •...

  • Page 314: Removing The Cylinder Head

    CYLINDER HEAD (YP250R) • Camshaft sprocket bolt “1” EAS24130 REMOVING THE CYLINDER HEAD • Camshaft sprocket plate “2” 1. Align: • Camshaft sprocket • “I” mark “a” on the generator rotor (with the stationary pointer “b” on the genera- To prevent the timing chain from falling into the tor cover) crankcase, fasten it with a wire “3”.

  • Page 315: Checking The Camshaft Sprocket

    CYLINDER HEAD (YP250R) To ensure an even surface, rotate the cylinder head several times. L LLL L LLL L LLL L LLL L LLL EAS23870 CHECKING THE CAMSHAFT SPROCKET 1. Check: • Camshaft sprocket More than 1/4 tooth wear “a” → Replace the camshaft sprocket, timing chain and crank- 2.

  • Page 316: Installing The Cylinder Head

    CYLINDER HEAD (YP250R) EAS24230 INSTALLING THE CYLINDER HEAD 1. Tighten: • Cylinder head nuts “1” Cylinder head nut 22 Nm (2.2 m·kgf, 16 ft·lbf) • Cylinder head bolts “2” Cylinder head bolt 10 Nm (1.0 m·kgf, 7.2 ft·lbf) • Lubricate the cylinder head nuts and washers with engine oil.
  • Page 317 CYLINDER HEAD (YP250R) c. Install the timing chain tensioner and gasket ECA37P1010 NOTICE “5” onto the cylinder. Be sure to tighten the camshaft sprocket bolt Timing chain tensioner bolt to the specified torque to avoid the possibil- 10 Nm (1.0 m·kgf, 7.2 ft·lbf) ity of the bolt coming loose and damaging the engine.

  • Page 318: Camshaft (Yp250R)

    CAMSHAFT (YP250R) EAS23730 CAMSHAFT (YP250R) Removing the rocker arms and camshaft 14 Nm (1.4 m kgf, 10 ft Ibf) • • 8 Nm (0.8 m kgf, 5.8 ft Ibf) • • 14 Nm (1.4 m kgf, 10 ft Ibf) • •...

  • Page 319: Removing The Rocker Arms And Camshaft

    CAMSHAFT (YP250R) EAS23770 REMOVING THE ROCKER ARMS AND CAMSHAFT 1. Straighten the lock plate tabs “a”. 2. Remove: • Lock plate “1” • Camshaft retainer “2” EAS23840 CHECKING THE CAMSHAFT 1. Check: • Camshaft lobes Blue discoloration/pitting/scratches → Re- place the camshaft. 2.

  • Page 320: Checking The Rocker Arms And Rocker Arm Shafts

    CAMSHAFT (YP250R) Rocker arm shaft outside diame- 11.981–11.991 mm (0.4717– 0.4721 in) Limit 11.950 mm (0.4705 in) 3. Check: • Camshaft oil passage Obstruction → Blow out with compressed air. EAS23880 CHECKING THE ROCKER ARMS AND ROCKER ARM SHAFTS The following procedure applies to all of the 5.
  • Page 321 CAMSHAFT (YP250R) 3. Install: • Exhaust rocker arm • Exhaust rocker arm shaft Make sure the exhaust rocker arm shaft is com- pletely pushed into the cylinder head. 4. Install: • Intake rocker arm • Intake rocker arm shaft “1” Insert a guide stud (8 mm) “2”...

  • Page 322: Valves And Valve Springs (Yp250R)

    VALVES AND VALVE SPRINGS (YP250R) EAS24270 VALVES AND VALVE SPRINGS (YP250R) Removing the valves and valve springs Order Job/Parts to remove Q’ty Remarks Refer to “CYLINDER HEAD (YP250R)” on Cylinder head page 5-67. Refer to “CAMSHAFT (YP250R)” on page Rocker arms/Camshaft 5-73.

  • Page 323: Removing The Valves

    VALVES AND VALVE SPRINGS (YP250R) EAS24280 REMOVING THE VALVES The following procedure applies to all of the valves and related components. Before removing the internal parts of the cylinder head (e.g., valves, valve springs, valve seats), make sure the valves properly seal. 1.
  • Page 324 VALVES AND VALVE SPRINGS (YP250R) b. Install a new clip and new valve guide with Valve-stem-to-valve-guide clear- the valve guide installer “2” and valve guide ance (intake) remover “1”. 0.010–0.037 mm (0.0004–0.0015 Limit 0.080 mm (0.0031 in) Valve-stem-to-valve-guide clear- ance (exhaust) 0.025–0.052 mm (0.0010–0.0020 Limit 0.100 mm (0.0039 in)

  • Page 325: Checking The Valve Seats

    VALVES AND VALVE SPRINGS (YP250R) • Valve stem end 2. Check: Mushroom shape or diameter larger than the • Valve seat body of the valve stem → Replace the valve. Pitting/wear → Replace the cylinder head. 5. Measure: 3. Measure: •...

  • Page 326: Checking The Valve Springs

    VALVES AND VALVE SPRINGS (YP250R) After replacing the cylinder head or replacing the valve and valve guide, the valve seat and valve face should be lapped. M MMM M MMM M MMM M MMM M MMM a. Apply a coarse lapping compound “a” to the valve face.

  • Page 327: Installing The Valves

    VALVES AND VALVE SPRINGS (YP250R) 3. Measure: • Valve spring tilt “a” Out of specification → Replace the valve spring. Inner spring Spring tilt (intake) 2.5°/1.7 mm Spring tilt (exhaust) 2.5°/1.7 mm Outer spring 2. Measure: Spring tilt (intake) • Compressed valve spring force “a” 2.5°/1.6 mm Out of specification →...
  • Page 328 VALVES AND VALVE SPRINGS (YP250R) Valve spring compressor 90890-04019 YM-04019 Valve spring compressor attach- ment 90890-04108 Valve spring compressor adapt- er 22 mm YM-04108 3. Install: • Lower spring seat “1” • Valve stem seal “2” • Valve “3” • Inner valve spring “4” •...

  • Page 329: Cylinder And Piston (Yp250R)

    CYLINDER AND PISTON (YP250R) EAS24350 CYLINDER AND PISTON (YP250R) Removing the cylinder and piston 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Refer to “CYLINDER HEAD (YP250R)” on Cylinder head page 5-67. Water pump outlet pipe Timing chain guide (exhaust side) Cylinder...

  • Page 330: Removing The Piston

    CYLINDER AND PISTON (YP250R) EAS24380 REMOVING THE PISTON When removing a piston ring, open the end gap 1. Remove: with your fingers and lift the other side of the ring • Piston pin clips “1” over the piston crown. • Piston pin “2” •...

  • Page 331: Checking The Piston Rings

    CYLINDER AND PISTON (YP250R) EAS24430 CHECKING THE PISTON RINGS 1. Measure: • Piston ring side clearance Out of specification → Replace the piston and piston rings as a set. Before measuring the piston ring side clearance, eliminate any carbon deposits from the piston ring grooves and piston rings.

  • Page 332: Checking The Piston Pin

    CYLINDER AND PISTON (YP250R) 3. Measure: 3. Measure: • Piston ring end gap • Piston pin bore diameter “b” Out of specification → Replace the piston Out of specification → Replace the piston. ring. Piston pin bore inside diameter 17.004–17.015 mm (0.6694– The oil ring expander spacer end gap cannot be 0.6699 in) measured.
  • Page 333 CYLINDER AND PISTON (YP250R) 120˚ 120˚ 120˚ 2. Install: a. Top ring • Piston “1” b. Upper oil ring rail • Piston pin “2” c. Oil ring expander d. Lower oil ring rail • Piston pin clips “3” e. 2nd ring f.

  • Page 334: V-Belt Automatic Transmission (Yp250R)

    V-BELT AUTOMATIC TRANSMISSION (YP250R) EAS24610 V-BELT AUTOMATIC TRANSMISSION (YP250R) Removing the V-belt case cover 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • (11) 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) •...
  • Page 335 V-BELT AUTOMATIC TRANSMISSION (YP250R) Removing the V-belt, primary sheave and secondary sheave 22 Nm (2.2 m kgf, 16 ft Ibf) • • 60 Nm (6.0 m kgf, 43 ft Ibf) • • 80 Nm (8.0 m kgf, 58 ft Ibf) •...
  • Page 336 • 3 Nm (0.3 m kgf, 2.2 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Spacer For installation, reverse the removal proce- dure. * Apply Shell BT grease 3® (Yamaha grease G 90793-40016). Yamaha grease G 90793-40016 5-91...
  • Page 337 V-BELT AUTOMATIC TRANSMISSION (YP250R) Disassembling the secondary sheave 90 Nm (9.0 m kgf, 65 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Clutch carrier nut Clutch carrier Clip Clutch carrier plate Clutch shoe spring Compression spring Spring seat Guide pin Secondary sliding sheave O-ring...

  • Page 338: Removing The Primary Sheave

    V-BELT AUTOMATIC TRANSMISSION (YP250R) EAS24620 REMOVING THE PRIMARY SHEAVE 1. Remove: • V-belt case Loosen each bolt 1/4 of a turn at a time, in stag- es and in a crisscross pattern. After all of the bolts are fully loosened, remove them. 2.

  • Page 339: Disassembling The Secondary Sheave

    V-BELT AUTOMATIC TRANSMISSION (YP250R) EAS24640 EAS24660 DISASSEMBLING THE SECONDARY CHECKING THE CLUTCH SHOES SHEAVE The following procedure applies to all of the 1. Remove: clutch shoes. • Clutch carrier nut “1” 1. Check: • Clutch shoe Damage/wear → Replace the clutch shoes While compressing the compression spring with and springs as a set.

  • Page 340: Checking The Primary Sheave

    V-BELT AUTOMATIC TRANSMISSION (YP250R) EAS24700 CHECKING THE PRIMARY SHEAVE V-belt width SLIDERS 23.0 mm (0.91 in) 1. Check: Limit 21.0 mm (0.83 in) • Primary sheave slider Cracks/damage/wear → Replace. EAS24710 CHECKING THE SECONDARY SHEAVE 1. Check: • Secondary fixed sheave •...

  • Page 341: Assembling The Secondary Sheave

    V-BELT AUTOMATIC TRANSMISSION (YP250R) • Primary sliding sheave • Spacer Install the secondary sliding sheave onto the • Primary sheave weights secondary fixed sheave “2” with the oil seal • Cam guide “3”. 2. Install: • Primary sheave weights “1” Oil seal guide (ø41) •...

  • Page 342: Installing The V-Belt

    V-BELT AUTOMATIC TRANSMISSION (YP250R) Clutch spring holder Clutch carrier nut 90890-01337 90 Nm (9.0 m·kgf, 65 ft·lbf) Clutch spring holder arm 90890-01464 While holding the clutch carrier with the sheave holder “2”, tighten the clutch carrier nut with the locknut wrench “3”. Sheave holder 90890-01701 Primary clutch holder...
  • Page 343 V-BELT AUTOMATIC TRANSMISSION (YP250R) 4. Install: • V-belt “1” • Make sure that the V-belt case gasket lip fits • Primary fixed sheave “2” properly around the V-belt case. • Washer • Tighten the V-belt case bolts in stages and in a •...

  • Page 344: Starter Clutch And Generator (Yp250R)

    STARTER CLUTCH AND GENERATOR (YP250R) EAS24480 STARTER CLUTCH AND GENERATOR (YP250R) Removing the generator cover and stator coil 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 8 Nm (0.8 m kgf, 5.8 ft Ibf) •...
  • Page 345 STARTER CLUTCH AND GENERATOR (YP250R) Removing the generator rotor and starter clutch 30 Nm (3.0 m kgf, 22 ft Ibf) • • 80 Nm (8.0 m kgf, 58 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Circlip Washer Starter clutch idle gear shaft Starter clutch idle gear Generator rotor...

  • Page 346: Removing The Generator

    STARTER CLUTCH AND GENERATOR (YP250R) EAS24490 REMOVING THE GENERATOR 1. Remove: • Generator cover Loosen each bolt 1/4 of a turn at a time, in stag- es and in a crisscross pattern. After all of the bolts are fully loosened, remove them. 2.

  • Page 347: Installing The Starter Clutch

    STARTER CLUTCH AND GENERATOR (YP250R) 2. Check: Sheave holder • Starter clutch idle gear 90890-01701 • Starter clutch gear Primary clutch holder Burrs/chips/roughness/wear → Replace the YS-01880-A defective part(s). 3. Check: • Starter clutch gear’s contact surfaces Damage/pitting/wear → Replace the starter clutch gear.
  • Page 348 Tighten the generator cover bolts in stages and in a crisscross pattern. 3. Apply: • Sealant (onto the crankshaft position sensor/stator assembly lead grommet) Yamaha bond No. 1215 90890-85505 (Three Bond No.1215®) 4. Install: • Oil seal “1” Installed depth “a”...

  • Page 349: Electric Starter (Yp250R)

    ELECTRIC STARTER (YP250R) EAS24780 ELECTRIC STARTER (YP250R) Removing the starter motor 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Refer to “GENERAL CHASSIS” on page Storage box/Air filter case 4-1. Starter motor lead Disconnect.
  • Page 350 ELECTRIC STARTER (YP250R) Disassembling the starter motor 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 5 Nm (0.5 m kgf, 3.6 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Starter motor front cover O-ring Shim Lock washer Oil seal Bearing Starter motor yoke...

  • Page 351: Checking The Starter Motor

    ELECTRIC STARTER (YP250R) EAS24790 CHECKING THE STARTER MOTOR Digital circuit tester 1. Check: 90890-03174 • Commutator Model 88 Multimeter with ta- Dirt → Clean with 600 grit sandpaper. chometer YU-A1927 2. Measure: • Commutator diameter “a” Out of specification → Replace the starter Armature coil motor.

  • Page 352: Assembling The Starter Motor

    ELECTRIC STARTER (YP250R) 7. Check: • Gear teeth Damage/wear → Replace the gear. 8. Check: • Bearing Damage/wear → Replace the bearing. EAS24800 ASSEMBLING THE STARTER MOTOR 1. Install: • Starter motor rear cover “1” • Starter motor yoke “2” •...

  • Page 353: Oil Pump (Yp250R)

    OIL PUMP (YP250R) EAS24910 OIL PUMP (YP250R) Removing the oil pump 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 12 Nm (1.2 m kgf, 8.7 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Refer to “STARTER CLUTCH AND GENER- Starter clutch gear ATOR (YP250R)”...
  • Page 354 OIL PUMP (YP250R) Removing the oil pump 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 12 Nm (1.2 m kgf, 8.7 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Oil pump housing For installation, reverse the removal proce- dure.

  • Page 355: Checking The Oil Pump

    OIL PUMP (YP250R) EAS24960 CHECKING THE OIL PUMP Inner-rotor-to-outer-rotor-tip 1. Check: clearance • Oil pump drive gear Less than 0.15 mm (0.0059 in) • Oil pump driven gear Limit 0.23 mm (0.0091 in) • Oil pump housing Outer-rotor-to-oil-pump-housing • Oil pump housing cover clearance Cracks/damage/wear →...

  • Page 356: Installing The Oil Pump

    OIL PUMP (YP250R) 4. Check: • Oil pump operation Refer to “CHECKING THE OIL PUMP” on page 5-110. EAS25020 INSTALLING THE OIL PUMP 1. Install: • Oil pump assembly Oil pump assembly bolt 7 Nm (0.7 m·kgf, 5.1 ft·lbf) ECA13890 NOTICE After tightening the bolts, make sure the oil pump turns smoothly.

  • Page 357: Transmission (Yp250R)

    TRANSMISSION (YP250R) EAS26240 TRANSMISSION (YP250R) Removing the transmission 16 Nm (1.6 m kgf, 11 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Rear wheel Refer to “REAR WHEEL” on page 4-15. Drain. Final transmission oil Refer to “CHANGING THE FINAL TRANS- MISSION OIL”...
  • Page 358 TRANSMISSION (YP250R) Removing the transmission 16 Nm (1.6 m kgf, 11 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Primary driven gear For installation, reverse the removal proce- dure. 5-113...

  • Page 359: Removing The Transmission

    TRANSMISSION (YP250R) EAS26250 REMOVING THE TRANSMISSION 1. Remove: • Transmission case cover Loosen each bolt 1/4 of a turn at a time, in stag- es and in a crisscross pattern. After all of the bolts are fully loosened, remove them. EAS26300 CHECKING THE TRANSMISSION 1.

  • Page 360: Crankshaft (Yp250R)

    CRANKSHAFT (YP250R) EAS25960 CRANKSHAFT (YP250R) Removing the crankshaft 22 Nm (2.2 m kgf, 16 ft Ibf) • • 32 Nm (3.2 m kgf, 23 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 20 Nm (2.0 m kgf, 14 ft Ibf) •...
  • Page 361 CRANKSHAFT (YP250R) Removing the crankshaft 22 Nm (2.2 m kgf, 16 ft Ibf) • • 32 Nm (3.2 m kgf, 23 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 20 Nm (2.0 m kgf, 14 ft Ibf) •...

  • Page 362: Disassembling The Crankcase

    CRANKSHAFT (YP250R) EAS25560 DISASSEMBLING THE CRANKCASE • Before removing the crankshaft assembly, re- 1. Remove: move the timing chain from the crankshaft • Crankcase bolts sprocket. • The crankshaft assembly cannot be removed if Loosen each bolt 1/4 of a turn at a time, in stag- the timing chain is attached onto the crankshaft es and in a crisscross pattern.

  • Page 363: Checking The Timing Chain And Timing Chain Guide

    CRANKSHAFT (YP250R) EAS24180 CHECKING THE TIMING CHAIN AND TIMING CHAIN GUIDE 1. Check: • Timing chain Damage/stiffness → Replace the timing chain and camshaft sprocket as a set. 3. Measure: • Crankshaft width Out of specification → Replace the crank- shaft.

  • Page 364: Checking The Crankcase

    CRANKSHAFT (YP250R) a. Oil seal installed depth EAS25580 CHECKING THE CRANKCASE 3. Install: 1. Thoroughly wash the crankcase halves in a • Timing chain “1” mild solvent. 2. Thoroughly clean all the gasket surfaces and crankcase mating surfaces. Install the timing chain so it is not visible through 3.

  • Page 365: Assembling The Crankcase

    2. Apply: • Sealant 4. Install: (onto the crankcase mating surfaces) • Water pump assembly Yamaha bond No. 1215 • Crankcase bolts 90890-85505 (Three Bond No.1215®) Crankcase bolt 10 Nm (1.0 m·kgf, 7.2 ft·lbf) Do not allow any sealant to come into contact with the oil gallery.
  • Page 366 CRANKSHAFT (YP250R) 5-121...
  • Page 367 COOLING SYSTEM RADIATOR (YP125R) ..................6-1 CHECKING THE RADIATOR..............6-2 INSTALLING THE RADIATOR..............6-2 THERMOSTAT (YP125R) ................6-3 CHECKING THE THERMOSTAT.............. 6-4 INSTALLING THE THERMOSTAT............6-4 WATER PUMP (YP125R)................6-5 DISASSEMBLING THE WATER PUMP............ 6-6 CHECKING THE WATER PUMP .............. 6-6 ASSEMBLING THE WATER PUMP............
  • Page 368 RADIATOR (YP125R) EAS37P1105 RADIATOR (YP125R) Removing the radiator 7 Nm (0.7 m kgf, 5.1 ft Ibf) 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft...

  • Page 369: Cooling System

    RADIATOR (YP125R) Refer to “CHANGING THE COOLANT” on EAS37P1106 CHECKING THE RADIATOR page 3-18. 1. Check: 3. Check: • Radiator fins • Cooling system Obstruction → Clean. Leaks → Repair or replace any faulty part. Apply compressed air to the rear of the radia- tor.

  • Page 370: Thermostat (Yp125R)

    THERMOSTAT (YP125R) EAS37P1108 THERMOSTAT (YP125R) Removing the thermostat 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Refer to “GENERAL CHASSIS” on page Storage box 4-1. Drain. Coolant Refer to “CHANGING THE COOLANT” on page 3-18.

  • Page 371: Checking The Thermostat

    THERMOSTAT (YP125R) EAS37P1109 CHECKING THE THERMOSTAT 1. Check: • Thermostat Does not open at 70.5–73.5 °C (158.9–164.3 °F) → Replace. M MMM M MMM M MMM M MMM M MMM a. Suspend the thermostat “1” in a container “2” filled with water.
  • Page 372 WATER PUMP (YP125R) EAS37P1111 WATER PUMP (YP125R) Removing the water pump 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) •...

  • Page 373: Disassembling The Water Pump

    WATER PUMP (YP125R) EAS37P1112 DISASSEMBLING THE WATER PUMP Install the water pump seal with the special tools 1. Remove: to the specified depth as shown in the illustra- • Water pump seal “1” tion. Remove the water pump seal from the inside of Installed depth of water pump the water pump housing “2”.

  • Page 374: Installing The Water Pump

    WATER PUMP (YP125R) • Water pump housing plate 1 “3” Refer to “CHANGING THE COOLANT” on page 3-18. Water pump housing plate 1 bolt 3. Check: 10 Nm (1.0 m·kgf, 7.2 ft·lbf) • Cooling system LOCTITE® Leaks → Repair or replace any faulty part.

  • Page 375: Radiator (Yp250R)

    RADIATOR (YP250R) EAS26380 RADIATOR (YP250R) Removing the radiator 7 Nm (0.7 m kgf, 5.1 ft Ibf) 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) •...

  • Page 376: Checking The Radiator

    RADIATOR (YP250R) Refer to “CHANGING THE COOLANT” on EAS26390 CHECKING THE RADIATOR page 3-32. 1. Check: 3. Check: • Radiator fins • Cooling system Obstruction → Clean. Leaks → Repair or replace any faulty part. Apply compressed air to the rear of the radia- tor.

  • Page 377: Thermostat (Yp250R)

    THERMOSTAT (YP250R) EAS26440 THERMOSTAT (YP250R) Removing the thermostat 3 Nm (0.3 m kgf, 2.2 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Refer to “GENERAL CHASSIS” on page Storage box 4-1.

  • Page 378: Checking The Thermostat

    THERMOSTAT (YP250R) EAS26450 CHECKING THE THERMOSTAT 1. Check: • Thermostat Does not open at 80.5–83.5 °C (176.9–182.3 °F) → Replace. M MMM M MMM M MMM M MMM M MMM a. Suspend the thermostat “1” in a container “2” filled with water. b.

  • Page 379: Water Pump (Yp250R)

    WATER PUMP (YP250R) EAS26500 WATER PUMP (YP250R) Removing the water pump 12 Nm (1.2 m kgf, 8.7 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • •...
  • Page 380 WATER PUMP (YP250R) Removing the water pump 12 Nm (1.2 m kgf, 8.7 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) •...

  • Page 381: Disassembling The Water Pump

    • Install the water pump seal with the special tools. Remove the bearing and oil seal from the out- • Before installing the water pump seal, apply side of the water pump housing. Yamaha bond No.1215 (Three Bond No.1215®) “2” to the water pump housing “3”. 6-14...

  • Page 382: Installing The Water Pump

    90890-04132 0.15 mm (0.0059 in) Water pump seal installer YM-33221-A Middle driven shaft bearing driv- 90890-04058 Bearing driver 40 mm YM-04058 Yamaha bond No. 1215 90890-85505 (Three Bond No.1215®) 1. Straightedge 2. Impeller 5. Install: • Impeller shaft • Circlip After installation, check that the impeller shaft ro- tates smoothly.
  • Page 383 REMOVING THE FUEL HOSE ..............7-9 CHECKING THE FUEL INJECTOR ............7-9 CHECKING THE THROTTLE BODY ............7-9 INSTALLING THE INTAKE MANIFOLD (YP125R) ........7-9 INSTALLING THE INTAKE MANIFOLD (YP250R) ........7-9 INSTALLING THE FUEL HOSE .............. 7-10 INSTALLING THE THROTTLE BODY ............ 7-10 CHECKING THE THROTTLE POSITION SENSOR .......

  • Page 384: Fuel Tank

    FUEL TANK EAS26620 FUEL TANK Removing the fuel tank 14 Nm (1.4 m kgf, 10 ft Ibf) 7 Nm (0.7 m kgf, 5.1 ft Ibf) 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • • • • • 14 Nm (1.4 m kgf, 10 ft Ibf) •...
  • Page 385 FUEL TANK Removing the fuel tank 14 Nm (1.4 m kgf, 10 ft Ibf) 10 Nm (1.0 m kgf, 7.2 ft Ibf) 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • • • • • 14 Nm (1.4 m kgf, 10 ft Ibf) •...

  • Page 386: Removing The Fuel Tank

    FUEL TANK 5. Remove: EAS26630 REMOVING THE FUEL TANK • Fuel tank 1. Extract the fuel in the fuel tank through the fuel tank filler hole with a pump. To remove the fuel tank, lower the radiator “1”. 2. Remove: •...

  • Page 387: Installing The Fuel Tank

    FUEL TANK 2. Install: Pressure gauge • Fuel hose 90890-03153 • Fuel hose connector cover YU-03153 ECA37P1022 Fuel pressure adapter NOTICE 90890-03181 When installing the fuel hose, make sure that it is securely connected, and that the fuel hose connector cover is in the correct posi- tion, otherwise the fuel hose will not be prop- erly installed.

  • Page 388: Throttle Body

    THROTTLE BODY EAS26970 THROTTLE BODY Removing the throttle body (YP125R) 10 Nm (1.0 m kgf, 7.2 ft Ibf) 10 Nm (1.0 m kgf, 7.2 ft Ibf) 1.5 Nm (0.15 m kgf, 1.1 ft Ibf) • • • • • •...
  • Page 389 THROTTLE BODY Removing the throttle body (YP125R) 10 Nm (1.0 m kgf, 7.2 ft Ibf) 10 Nm (1.0 m kgf, 7.2 ft Ibf) 1.5 Nm (0.15 m kgf, 1.1 ft Ibf) • • • • • • 10 Nm (1.0 m kgf, 7.2 ft...
  • Page 390 THROTTLE BODY Removing the throttle body (YP250R) 10 Nm (1.0 m kgf, 7.2 ft Ibf) 2 Nm (0.2 m kgf, 1.4 ft Ibf) • • • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 3 Nm (0.3 m kgf, 2.2 ft Ibf) •...
  • Page 391 THROTTLE BODY Removing the throttle body (YP250R) 10 Nm (1.0 m kgf, 7.2 ft Ibf) 2 Nm (0.2 m kgf, 1.4 ft Ibf) • • • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 3 Nm (0.3 m kgf, 2.2 ft Ibf) •...

  • Page 392: Removing The Fuel Hose

    Before removing the hose, place a few rags in the area under where it will be removed. EAS37P1116 INSTALLING THE INTAKE MANIFOLD (YP125R) 1. Install: • Intake manifold joint “1” • Intake manifold “2” EAS26980 Make sure that the projection “a”...

  • Page 393: Installing The Fuel Hose

    A. YP125R • Wipe up any fuel remaining in the recess “a” in B. YP250R the fuel pump with a dry rag “1”.
  • Page 394 THROTTLE BODY 7-11...
  • Page 395 ELECTRICAL SYSTEM IGNITION SYSTEM ..................8-1 CIRCUIT DIAGRAM .................. 8-1 TROUBLESHOOTING ................8-3 ELECTRIC STARTING SYSTEM ..............8-5 CIRCUIT DIAGRAM .................. 8-5 STARTING CIRCUIT CUT-OFF SYSTEM OPERATION ......8-7 TROUBLESHOOTING ................8-9 CHARGING SYSTEM..................8-11 CIRCUIT DIAGRAM ................8-11 TROUBLESHOOTING ................8-13 LIGHTING SYSTEM ..................
  • Page 396 ELECTRICAL COMPONENTS..............8-71 CHECKING THE SWITCHES ..............8-73 CHECKING THE BULBS AND BULB SOCKETS ........8-76 CHECKING THE FUSES ................ 8-77 CHECKING AND CHARGING THE BATTERY........8-78 CHECKING THE RELAYS ..............8-80 CHECKING THE TURN SIGNAL/HAZARD RELAY........ 8-81 CHECKING THE SPARK PLUG CAP ............. 8-82 CHECKING THE IGNITION COIL ............

  • Page 398: Ignition System

    IGNITION SYSTEM EAS27090 IGNITION SYSTEM EAS27100 CIRCUIT DIAGRAM...
  • Page 399 IGNITION SYSTEM 2. Crankshaft position sensor 5. Main switch 6. ECU fuse 9. Ignition fuse 12.Battery 13.Main fuse 17.Frame ground 18.Sidestand switch 29.Lean angle sensor 31.ECU (engine control unit) 32.Ignition coil 33.Spark plug...

  • Page 400: Troubleshooting

    IGNITION SYSTEM EAS27120 TROUBLESHOOTING The ignition system fails to operate (no spark or intermittent spark). • Before troubleshooting, remove the following part(s): 1. Storage box 2. Front cowling 3. Storage compartment 4. Footrest board NG → 1. Check the fuses. (Main, ECU, and ignition) Replace the fuse(s).
  • Page 401 IGNITION SYSTEM NG → 8. Check the main switch. Refer to “CHECKING THE Replace the main switch/immobilizer unit. SWITCHES” on page 8-73. OK ↓ NG → 9. Check the sidestand switch. Refer to “CHECKING THE Replace the sidestand switch. SWITCHES” on page 8-73. OK ↓...

  • Page 402: Electric Starting System

    ELECTRIC STARTING SYSTEM EAS27160 ELECTRIC STARTING SYSTEM EAS27170 CIRCUIT DIAGRAM...
  • Page 403 ELECTRIC STARTING SYSTEM 5. Main switch 9. Ignition fuse 11.Signaling system fuse 12.Battery 13.Main fuse 14.Starter relay 15.Starter motor 16.Diode 17.Frame ground 18.Sidestand switch 20.Starting circuit cut-off relay 22.Start switch 24.Front brake light switch 46.Rear brake light switch...

  • Page 404: Starting Circuit Cut-Off System Operation

    ELECTRIC STARTING SYSTEM EAS27180 STARTING CIRCUIT CUT-OFF SYSTEM OPERATION If the main switch is set to “ON” (switch circuit is closed), the starter motor can only operate if the fol- lowing conditions are met: • The brake lever is pulled to the handlebar (the brake switch is closed) and the sidestand is up (the sidestand switch is closed).
  • Page 405 ELECTRIC STARTING SYSTEM 1. Battery 2. Main fuse 3. Main switch 4. Ignition fuse 5. Starting circuit cut-off relay 6. Sidestand switch 7. Signaling system fuse 8. Front brake light switch 9. Rear brake light switch 10. Start switch 11. Diode 12.

  • Page 406: Troubleshooting

    ELECTRIC STARTING SYSTEM EAS27190 TROUBLESHOOTING The starter motor fails to turn. • Before troubleshooting, remove the following part(s): 1. Storage box 2. Front cowling 3. Storage compartment NG → 1. Check the fuses. (Main, ignition, and signaling sys- tem) Replace the fuse(s). Refer to “CHECKING THE FUS- ES”...
  • Page 407 ELECTRIC STARTING SYSTEM NG → 8. Check the sidestand switch. Refer to “CHECKING THE Replace the sidestand switch. SWITCHES” on page 8-73. OK ↓ NG → 9. Check the brake light switches (front and rear). Replace the brake light switch(es). Refer to “CHECKING THE SWITCHES”...

  • Page 408: Charging System

    CHARGING SYSTEM EAS27200 CHARGING SYSTEM EAS27210 CIRCUIT DIAGRAM 8-11...
  • Page 409 CHARGING SYSTEM 1. AC magneto 3. Rectifier/regulator 12.Battery 13.Main fuse 17.Frame ground 8-12...

  • Page 410: Troubleshooting

    CHARGING SYSTEM EAS27230 TROUBLESHOOTING The battery is not being charged. • Before troubleshooting, remove the following part(s): 1. Storage box 2. Front cowling NG → 1. Check the fuse. (Main) Replace the fuse. Refer to “CHECKING THE FUS- ES” on page 8-77. OK ↓...
  • Page 411 CHARGING SYSTEM 8-14...

  • Page 412: Lighting System

    LIGHTING SYSTEM EAS27240 LIGHTING SYSTEM EAS27250 CIRCUIT DIAGRAM 8-15...
  • Page 413 LIGHTING SYSTEM 5. Main switch 6. ECU fuse 8. Turn signal/hazard fuse 9. Ignition fuse 10.Headlight fuse 11.Signaling system fuse 12.Battery 13.Main fuse 17.Frame ground 31.ECU (engine control unit) 40.Headlight relay 42.Dimmer switch 43.Pass switch 49.Tail/brake light 55.Headlight 56.Auxiliary light 57.License plate light 68.Meter light 69.High beam indicator light...

  • Page 414: Troubleshooting

    LIGHTING SYSTEM EAS27260 TROUBLESHOOTING Any of the following fail to light: headlight, high beam indicator light, taillights, license plate light, auxiliary lights or meter light. • Before troubleshooting, remove the following part(s): 1. Front cowling NG → 1. Check the condition of each bulb and bulb socket.
  • Page 415 LIGHTING SYSTEM NG → 8. Check the entire lighting system wiring. Properly connect or repair the lighting sys- Refer to “CIRCUIT DIAGRAM” on tem wiring. page 8-15. OK ↓ Replace the ECU or meter assembly. 8-18...

  • Page 416: Signaling System

    SIGNALING SYSTEM EAS27270 SIGNALING SYSTEM EAS27280 CIRCUIT DIAGRAM 8-19...
  • Page 417 SIGNALING SYSTEM 2. Crankshaft position sensor 5. Main switch 6. ECU fuse 8. Turn signal/hazard fuse 9. Ignition fuse 11.Signaling system fuse 12.Battery 13.Main fuse 17.Frame ground 23.Hazard switch 24.Front brake light switch 25.Coolant temperature sensor 30.Speed sensor 31.ECU (engine control unit) 38.Horn 39.Turn signal/hazard relay 44.Turn signal switch...

  • Page 418: Troubleshooting

    SIGNALING SYSTEM EAS27290 TROUBLESHOOTING • Any of the following fail to light: turn signal lights, brake lights, warning light or indicator lights. • The horn fails to sound. • The fuel meter fails to operate. • The coolant temperature meter fails to operate. •...
  • Page 419 SIGNALING SYSTEM NG → 2. Check the horn. Refer to “CHECKING THE HORN” Replace the horn. on page 8-85. OK ↓ NG → 3. Check the entire signaling system wiring. Properly connect or repair the signaling Refer to “CIRCUIT DIAGRAM” on system wiring.
  • Page 420 SIGNALING SYSTEM NG → 2. Check the turn signal switch. The turn signal switch is faulty. Replace Refer to “CHECKING THE the left handlebar switch. SWITCHES” on page 8-73. OK ↓ NG → 3. Check the hazard switch. The hazard switch is faulty. Replace the Refer to “CHECKING THE right handlebar switch.
  • Page 421 SIGNALING SYSTEM NG → 2. Check the entire signaling system wiring. Properly connect or repair the signaling Refer to “CIRCUIT DIAGRAM” on system wiring. page 8-19. OK ↓ Replace the ECU or meter assembly. The speedometer fails to operate. NG → 1.
  • Page 422 SIGNALING SYSTEM NG → 2. Check the entire signaling system wiring. Properly connect or repair the signaling Refer to “CIRCUIT DIAGRAM” on system wiring. page 8-19. OK ↓ Replace the meter assembly. The V-belt replacement indicator fails to come on. NG →...
  • Page 423 SIGNALING SYSTEM 8-26...

  • Page 424: Cooling System

    COOLING SYSTEM EAS27300 COOLING SYSTEM EAS27310 CIRCUIT DIAGRAM 8-27...
  • Page 425 COOLING SYSTEM 5. Main switch 6. ECU fuse 7. Radiator fan motor fuse 9. Ignition fuse 12.Battery 13.Main fuse 17.Frame ground 25.Coolant temperature sensor 31.ECU (engine control unit) 73.Radiator fan motor 74.Radiator fan motor relay 8-28...

  • Page 426: Troubleshooting

    COOLING SYSTEM EAS27320 TROUBLESHOOTING • The radiator fan motor fails to turn. • Before troubleshooting, remove the following part(s): 1. Storage box 2. Front cowling 3. Radiator cover NG → 1. Check the fuses. (Main, ignition, ECU, and radiator fan motor) Replace the fuse(s).
  • Page 427 COOLING SYSTEM 8-30...

  • Page 428: Fuel Injection System

    FUEL INJECTION SYSTEM EAS27330 FUEL INJECTION SYSTEM EAS27340 CIRCUIT DIAGRAM 8-31...
  • Page 429 FUEL INJECTION SYSTEM 2. Crankshaft position sensor 4. Backup fuse (immobilizer unit and meter assembly) 5. Main switch 6. ECU fuse 7. Radiator fan motor fuse 9. Ignition fuse 10.Headlight fuse 12.Battery 13.Main fuse 17.Frame ground 18.Sidestand switch 19.Fuel pump 25.Coolant temperature sensor 26.Throttle position sensor 27.Intake air pressure sensor...

  • Page 430: Ecu Self-Diagnostic Function

    FUEL INJECTION SYSTEM EAS27350 ECU SELF-DIAGNOSTIC FUNCTION The ECU is equipped with a self-diagnostic function in order to ensure that the fuel injection system is operating normally. If this function detects a malfunction in the system, it immediately operates the en- gine under substitute characteristics and illuminates the engine trouble warning light to alert the rider that a malfunction has occurred in the system.

  • Page 431: Troubleshooting Method

    FUEL INJECTION SYSTEM When an abnormal signal is received from a sensor, the ECU processes the specified values that are programmed for each sensor in order to provide the engine with alternate operating instructions that enable the engine to continue operating or stop operating, depending on the conditions. 3.
  • Page 432 FUEL INJECTION SYSTEM Setting the diagnostic mode 1. Set the main switch to “OFF”. 2. Disconnect the self-diagnosis signal coupler, and then connect the FI diagnostic tool “1” as shown. 3. While pressing the “MODE” button, set the main switch to “ON”. •...

  • Page 433: Troubleshooting Details

    FUEL INJECTION SYSTEM • If a diagnostic code number does not have a corresponding fault code number, the information is shown in “DIAGNOSTIC CODE TABLE”. (Refer to “DIAGNOSTIC CODE TABLE” on page 8-54.) EAS27481 TROUBLESHOOTING DETAILS This section describes the measures per fault code number displayed on the meter. Check and service the items or components that are the probable cause of the malfunction following the order given.
  • Page 434 FUEL INJECTION SYSTEM Fault code No. Item Intake air pressure sensor: open or short circuit detected. Able to start engine Fail-safe system Able to drive vehicle Diagnostic code No. FI diagnostic tool display Displays the intake air pressure. Operate the throttle while pulling the brake lever and pushing the Checking method start switch “...
  • Page 435 FUEL INJECTION SYSTEM Fault code No. Intake air pressure sensor: hose line malfunction (clogged or Item detached hose). Connections • Check the coupler for any pins that may be • Intake air pressure sensor coupler pulled out. • Wire harness ECU coupler •...
  • Page 436 FUEL INJECTION SYSTEM Fault code No. Throttle position sensor: stuck throttle position sensor is de- Item tected. Able to start engine Fail-safe system Able to drive vehicle Diagnostic code No. Throttle angle FI diagnostic tool display • 9–22 (fully closed position) •...
  • Page 437 FUEL INJECTION SYSTEM Fault code No. Sidestand switch: a break or disconnection of the blue/yellow Item lead of the ECU is detected. Reinstatement method Reconnecting the wiring and retracting the sidestand. Fault code No. Item Coolant temperature sensor: open or short circuit detected. Able to start engine Fail-safe system Able to drive vehicle...
  • Page 438 FUEL INJECTION SYSTEM Fault code No. Item Intake air temperature sensor: open or short circuit detected. Installed condition of intake air tempera- • Check for looseness or pinching. ture sensor. Connections • Check the coupler for any pins that may be •...
  • Page 439 FUEL INJECTION SYSTEM Fault code No. sensor: no normal signal is received from the O sensor. Item Reinstatement method Starting the engine and operating it at idle. Fault code No. Latch up detected. Item No normal signal is received from the lean angle sensor. Unable to start engine Fail-safe system Unable to drive vehicle...
  • Page 440 FUEL INJECTION SYSTEM Fault code No. sensor: The amount of air-fuel ratio feedback compensa- Item tion is maintained continuously in the vicinity of the upper lim- Installed condition of O sensor. • Check for looseness or pinching. Connections • Check the coupler for any pins that may be •...
  • Page 441 FUEL INJECTION SYSTEM Fault code No. sensor: The amount of air-fuel ratio feedback compensa- Item tion is maintained continuously in the vicinity of the lower lim- Check fuel pressure. • Refer to “CHECKING THE FUEL PRESSURE” on page 7-3. Defective O sensor.
  • Page 442 FUEL INJECTION SYSTEM Fault code No. Item ISC valve: engine speed is high when the engine is idling. Able to start engine Fail-safe system Able to drive vehicle Diagnostic code No. Actuates and fully closes the ISC valve, then opens it to the stand- by opening position when the engine is started.
  • Page 443 FUEL INJECTION SYSTEM Fault code No. Item Injector: open or short circuit detected. Probable cause of malfunction Check or maintenance job Connections • Check the couplers for any pins that may be • Injector coupler pulled out. • Wire harness ECU coupler •...
  • Page 444 FUEL INJECTION SYSTEM Fault code No. Speed sensor: no normal signals are received from the speed Item sensor. Able to start engine Fail-safe system Able to drive vehicle Diagnostic code No. FI diagnostic tool display 0–999 Check that the number increases when the front wheel is rotated. Checking method The number is cumulative and does not reset each time the wheel is stopped.
  • Page 445 FUEL INJECTION SYSTEM Fault code No. Fuel system voltage: the ECU is unable to monitor the battery Item voltage (an open or short circuit in the line to the ECU). Compare with the actually measured battery voltage. (If the bat- Checking method tery voltage is low, perform recharging.) Probable cause of malfunction...
  • Page 446 FUEL INJECTION SYSTEM Fault code No. Item Power supply to the fuel injection system is not normal. Able to start engine Fail-safe system Able to drive vehicle Diagnostic code No. — FI diagnostic tool display — Checking method — Probable cause of malfunction Check or maintenance job Connections •...
  • Page 447 FUEL INJECTION SYSTEM Fault code No. Item ISC (idle speed control) unit: open or short circuit detected. Able to start engine Fail-safe system Able to drive vehicle Diagnostic code No. Actuates and fully closes the ISC valve, then opens it to the stand- by opening position when the engine is started.
  • Page 448 FUEL INJECTION SYSTEM Fault code No. Er-1 ECU internal malfunction (output signal error): no signals are Item received from the ECU. Open or short circuit in wire harness. • Repair or replace if there is an open or short circuit. •...
  • Page 449 FUEL INJECTION SYSTEM Fault code No. Er-3 ECU internal malfunction (output signal error): data from the Item ECU cannot be received correctly. Able to start engine Fail-safe system Able to drive vehicle Diagnostic code No. — Meter display — Checking method —...
  • Page 450 FUEL INJECTION SYSTEM Fault code No. Er-4 ECU internal malfunction (input signal error): non-registered Item data has been received from the meter. Open or short circuit in wire harness. • Repair or replace if there is an open or short circuit.

  • Page 451: Diagnostic Code Table

    FUEL INJECTION SYSTEM EAS30700 DIAGNOSTIC CODE TABLE The following tables contain information about diagnostic code numbers that do not have a correspond- ing fault code number. (These items are not listed in “TROUBLESHOOTING DETAILS”.) Diag- nostic FI diagnostic tool dis- Item Procedure code...
  • Page 452 FUEL INJECTION SYSTEM Communication error with the FI diagnostic tool LCD Display Symptom Probable cause of malfunction • Improper connection in connecting lead. Waiting for con- No signals are received • The main switch is set to “OFF”. nection..from the ECU. •...
  • Page 453 FUEL INJECTION SYSTEM 8-56...

  • Page 454: Fuel Pump System

    FUEL PUMP SYSTEM EAS27550 FUEL PUMP SYSTEM EAS27560 CIRCUIT DIAGRAM 8-57...
  • Page 455 FUEL PUMP SYSTEM 5. Main switch 6. ECU fuse 9. Ignition fuse 12.Battery 13.Main fuse 17.Frame ground 19.Fuel pump 31.ECU (engine control unit) 8-58...

  • Page 456: Troubleshooting

    FUEL PUMP SYSTEM EAS27570 TROUBLESHOOTING If the fuel pump fails to operate. • Before troubleshooting, remove the following part(s): 1. Storage box 2. Front cowling NG → 1. Check the fuses. (Main, ECU, and ignition) Replace the fuse(s). Refer to “CHECKING THE FUS- ES”...
  • Page 457 FUEL PUMP SYSTEM 8-60...

  • Page 458: Immobilizer System

    IMMOBILIZER SYSTEM EAS27640 IMMOBILIZER SYSTEM EAS27650 CIRCUIT DIAGRAM 8-61...
  • Page 459 IMMOBILIZER SYSTEM 4. Backup fuse (immobilizer unit and meter assembly) 5. Main switch 6. ECU fuse 9. Ignition fuse 12.Battery 13.Main fuse 17.Frame ground 31.ECU (engine control unit) 61.Immobilizer system indicator light 62.Multifunction meter 75.Self-diagnosis signal coupler 76.Immobilizer unit 8-62...

  • Page 460: General Information

    IMMOBILIZER SYSTEM EAS27670 GENERAL INFORMATION This vehicle is equipped with an immobilizer system to help prevent theft by re-registering codes in the standard keys. This system consists of the following: • a code re-registering key (with a red bow) • two standard keys (with a black bow) that can be re-registered with new codes •...
  • Page 461 IMMOBILIZER SYSTEM Parts to be replaced Main switch/immo- Key registration re- Accesso- bilizer unit Standard quirement ry lock* Main Immobiliz- and key switch er unit √ Standard key is lost New standard key All keys have been Code re-registering √ √...
  • Page 462 IMMOBILIZER SYSTEM Standby mode a. Main switch “ON” e. Standby mode on b. Main switch “OFF” f. Standby mode off c. LED on d. LED off Standard key registration: Standard key registration is required when a standard key is lost and needs to be replaced, or when the code re-registering key is re-registered after the immobilizer unit or ECU are replaced.
  • Page 463 IMMOBILIZER SYSTEM Standard key registration a. Main switch “ON” B. Immobilizer system indicator light stops flashing when the registration of the second b. Main switch “OFF” standard key is complete. c. LED on d. LED off e. Less than 5.0 s f.

  • Page 464: Troubleshooting

    IMMOBILIZER SYSTEM EAS27700 TROUBLESHOOTING When the main switch is turned to “ON”, the immobilizer system indicator light does not come on nor flashes. NG → 1. Check the fuses. (Main, ignition, ECU, and backup) Replace the fuse(s). Refer to “CHECKING THE FUS- ES”...
  • Page 465 IMMOBILIZER SYSTEM Fault Part Symptom Cause Action code IMMOBILIZER Codes between the 1. Signal received from 1. Place the immo- UNIT key and immobilizer other transponder bilizer unit at unit do not match. (failed to recognize least 50 mm code after ten con- away from the secutive attempts).
  • Page 466 IMMOBILIZER SYSTEM a. Light on b. Light off 8-69...
  • Page 467 IMMOBILIZER SYSTEM 8-70...

  • Page 468: Electrical Components

    ELECTRICAL COMPONENTS EAS27970 ELECTRICAL COMPONENTS 8-71...
  • Page 469 ELECTRICAL COMPONENTS 1. Battery 2. Air temperature sensor 3. ECU (engine control unit) 4. Front brake light switch 5. Rear brake light switch 6. Main switch/immobilizer unit 7. Fuel sender 8. Ignition coil 9. Fuel injector 10. Intake air temperature sensor 11.

  • Page 470: Checking The Switches

    ELECTRICAL COMPONENTS EAS27980 CHECKING THE SWITCHES L/W W/Y Br/W Ch R Br/L Br/R Br/R OPEN LOCK Br/L Br/W Ch Br/W L/B G Y (BLUE) R/Y Y Br/W Ch 8-73...
  • Page 471 ELECTRICAL COMPONENTS 1. Start switch 2. Hazard switch 3. Front brake light switch 4. Main switch 5. Dimmer switch 6. Pass switch 7. Turn signal switch 8. Horn switch 9. Rear brake light switch 10. Sidestand switch 8-74...
  • Page 472 ELECTRICAL COMPONENTS Check each switch for continuity with the pocket tester. If the continuity reading is incorrect, check the wiring connections and, if necessary, replace the switch. ECA14370 NOTICE Never insert the tester probes into the coupler terminal slots “a”. Always insert the probes from the opposite end of the coupler, taking care not to loosen or damage the leads.

  • Page 473: Checking The Bulbs And Bulb Sockets

    ELECTRICAL COMPONENTS EAS27990 EWA37P1018 CHECKING THE BULBS AND BULB WARNING SOCKETS Since headlight bulbs get extremely hot, keep flammable products and your hands Do not check any of the lights that use LEDs. away from them until they have cooled down.

  • Page 474: Checking The Fuses

    ELECTRICAL COMPONENTS Checking the condition of the bulb sockets Amperage Fuses Q’ty The following procedure applies to all of the bulb rating sockets. Backup (immobilizer 1. Check: 5.0 A and meter assembly) • Bulb socket (for continuity) (with the pocket tester) Spare 30.0 A No continuity →...

  • Page 475: Checking And Charging The Battery

    ELECTRICAL COMPONENTS c. Set on the switches to verify if the electrical ECA13661 NOTICE circuit is operational. • This is a VRLA (Valve Regulated Lead Acid) d. If the fuse immediately blows again, check battery. Never remove the sealing caps be- the electrical circuit.
  • Page 476 ELECTRICAL COMPONENTS 5. Charge: • Positive tester probe → • Battery positive battery terminal • Negative tester probe → (refer to the appropriate charging method) negative battery terminal EWA13300 WARNING Do not quick charge a battery. • The charge state of a VRLA (Valve Regulated ECA13671 Lead Acid) battery can be checked by measur- NOTICE...

  • Page 477: Checking The Relays

    ELECTRICAL COMPONENTS 7. Connect: • Battery leads (to the battery terminals) ECA13630 NOTICE First, connect the positive battery lead “1”, and then the negative battery lead “2”. A. Open-circuit voltage (V) B. Time (minutes) C. Charging D. Ambient temperature 20 °C (68 °F) E.

  • Page 478: Checking The Turn Signal/Hazard Relay

    ELECTRICAL COMPONENTS Starting circuit cut-off relay 2. Negative battery terminal 3. Positive tester probe 4. Negative tester probe Result Continuity (between “3” and “4”) L/Y G/Y Radiator fan motor relay 1. Positive battery terminal 2. Negative battery terminal 3. Positive tester probe 4.

  • Page 479: Checking The Spark Plug Cap

    ELECTRICAL COMPONENTS EAS28060 CHECKING THE SPARK PLUG CAP 1. Check: • Spark plug cap resistance Out of specification → Replace. Resistance Br/R 10.0 kΩ M MMM M MMM M MMM M MMM M MMM a. Remove the spark plug cap from the spark plug lead.

  • Page 480: Checking The Ignition Spark Gap

    ELECTRICAL COMPONENTS Refer to “TROUBLESHOOTING” on page 8-3. Minimum ignition spark gap 6.0 mm (0.24 in) If the ignition spark gap is within specification, the ignition system circuit is operating normally. M MMM M MMM M MMM M MMM M MMM c.

  • Page 481: Checking The Lean Angle Sensor

    ELECTRICAL COMPONENTS Pocket tester 45˚ 90890-03112 45˚ Analog pocket tester YU-03112-C • Positive tester probe → red “1” Gy/R Y/G Gy/B • Negative tester probe → white “2” c. Set the main switch to “ON”. d. Turn the lean angle sensor 45°. e.

  • Page 482: Checking The Stator Coil

    Stator coil resistance a. Connect the engine tachometer to the spark 0.28–0.42 Ω at 20 °C (68 °F) plug lead. (YP125R) b. Connect the pocket tester (DC 20 V) to the 0.32–0.48 Ω at 20 °C (68 °F) battery as shown.

  • Page 483: Checking The Fuel Sender

    ELECTRICAL COMPONENTS Pocket tester 90890-03112 Analog pocket tester YU-03112-C • Positive tester probe → horn terminal “1” • Negative tester probe → horn terminal “2” c. Measure the horn resistance. A. Full fuel tank position L LLL L LLL L LLL L LLL L LLL B.

  • Page 484: Checking The Speed Sensor

    90890-03112 SENSOR Analog pocket tester 1. Remove: YU-03112-C • Coolant temperature sensor Refer to “CYLINDER HEAD (YP125R)” on • Positive tester probe → page 5-7 and “CYLINDER HEAD (YP250R)” gray “1” on page 5-67. • Negative tester probe → EWA14130 gray/black “2”...

  • Page 485: Checking The Throttle Position Sensor

    ELECTRICAL COMPONENTS Throttle position sensor voltage (gray/red–gray/black) c. Connect the digital circuit tester to the throttle position sensor as shown. • Positive tester probe → yellow “1” • Negative tester probe → gray/black “2” d. Heat the coolant or let it cool down to the specified temperatures.

  • Page 486: Checking The Intake Air Temperature Sensor

    ELECTRICAL COMPONENTS Test harness Pocket tester 90890-03204 90890-03112 Pocket tester Analog pocket tester 90890-03112 YU-03112-C Analog pocket tester YU-03112-C b. Immerse the intake air temperature sensor “1” in a container filled with water “2”. • Positive tester probe → pink/white “1” Make sure that the intake air temperature sensor •...

  • Page 487: Checking The Isc (Idle Speed Control) Unit

    ELECTRICAL COMPONENTS • Positive tester probe → Pocket tester green “3” 90890-03112 • Negative tester probe → Analog pocket tester sky blue “4” YU-03112-C b. Immerse the air temperature sensor “1” in a container filled with water “2”. Make sure that the air temperature sensor termi- nals do not get wet.
  • Page 488 ELECTRICAL COMPONENTS M MMM M MMM M MMM M MMM M MMM a. Connect the pocket tester (Ω × 1) to the V- belt replacement indicator reset coupler ter- minals. Pocket tester 90890-03112 Analog pocket tester YU-03112-C b. Check the V-belt replacement indicator reset coupler for continuity.
  • Page 489 TROUBLESHOOTING TROUBLESHOOTING..................9-1 GENERAL INFORMATION ............... 9-1 STARTING FAILURE/HARD STARTING..........9-1 INCORRECT ENGINE IDLING SPEED ............ 9-1 POOR MEDIUM-AND-HIGH-SPEED PERFORMANCE ......9-2 FAULTY CLUTCH ..................9-2 OVERHEATING ..................9-2 OVERCOOLING..................9-3 POOR BRAKING PERFORMANCE............9-3 FAULTY FRONT FORK LEGS..............9-3 UNSTABLE HANDLING ................

  • Page 490: Fuel System

    TROUBLESHOOTING Electrical system EAS28450 TROUBLESHOOTING 1. Battery • Discharged battery EAS28460 • Faulty battery GENERAL INFORMATION 2. Fuse(s) • Blown, damaged or incorrect fuse The following guide for troubleshooting does not • Improperly installed fuse cover all the possible causes of trouble. It should 3.

  • Page 491: Troubleshooting

    TROUBLESHOOTING • Faulty battery 2. Primary sliding sheave 2. Spark plug • Faulty operation • Incorrect spark plug gap 3. Clutch shoe(s) • Incorrect spark plug heat range • Bent, damaged or worn clutch shoe • Fouled spark plug Poor speed performance •...

  • Page 492: Overcooling

    TROUBLESHOOTING Chassis EAS28670 UNSTABLE HANDLING 1. Brake(s) 1. Handlebar • Dragging brake • Bent or improperly installed handlebar 2. Steering head components Electrical system • Improperly installed lower handlebar holder 1. Spark plug • Improperly installed lower bracket • Incorrect spark plug gap (improperly tightened ring nut) •...
  • Page 493 TROUBLESHOOTING • Improperly grounded circuit • Faulty main switch • Headlight bulb life expired Tail/brake light does not come on • Wrong tail/brake light bulb • Too many electrical accessories • Incorrect connection • Burnt-out tail/brake light bulb Tail/brake light bulb burnt out •...

  • Page 494: Wiring Diagram

    EAS28740 57. License plate light EAS28750 WIRING DIAGRAM COLOR CODE 58. Fuel sender Black 59. V-belt replacement indicator re- YP125R/YP250R 2010 Brown set coupler 1. AC magneto Chocolate 60. Meter assembly 2. Crankshaft position sensor Dark green 61. Immobilizer system indicator 3.
  • Page 496 YAMAHA MOTOR ESPAÑA, S.A.
  • Page 497 YP125R/YP250R 2010 YP125R/YP250R 2010 YP125R/YP250R 2010 YP125R/YP250R 2010 YP125R/YP250R 2010 WIRING DIAGRAM SCHÉMA DE CÂBLAGE SCHALTPLAN SCHEMA ELETTRICO DIAGRAMA ELÉCTRICO Gy/B Y/G Br/W L B/W W/R L/Y L/W L/R Gy/B W/R Y Gy/G Gy/R Gy/B Gy/B W W2 G/Y R/B...
  • Page 498 YP125R/YP250R 2010 YP125R/YP250R 2010 YP125R/YP250R 2010 YP125R/YP250R 2010 YP125R/YP250R 2010 WIRING DIAGRAM SCHÉMA DE CÂBLAGE SCHALTPLAN SCHEMA ELETTRICO DIAGRAMA ELÉCTRICO (BLUE) (BLACK) (BLUE) (BLACK) (BLUE) WIRE HARNESS SUB-WIRE HARNESS (BLACK) (BLACK) (BLACK) (GREEN) OPEN LOCK (BLACK) (BLACK) (BLACK) (BLACK) (BLACK)

This manual is also suitable for:

2010 xmax yp250rXmax 125Xmax yp125rXmax yp125ra

Table of Contents