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Table of Contents
KX125
KX250
Motorcycle
Service Manual

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Table of Contents

   Also See for Kawasaki KX125

   Summary of Contents for Kawasaki KX125

  • Page 1 KX125 KX250 Motorcycle Service Manual...
  • Page 3: General Information

    Quick Reference Guide General Information Periodic Maintenance Fuel System Cooling System Engine Top End Engine Right Side Engine Removal/Installation Engine Bottom End/Transmission 8 j Wheels/Tires Final Drive 10 j Brakes 11 j Suspension 12 j Steering 13 j Electrical System 14 j Appendix 15 j...
  • Page 5 All information contained in this publication is based on the latest product information available at the time of publication. Illustrations and photographs in this publication are intended for reference use only and may not depict actual model component parts. © 2002 Kawasaki Heavy Industries, Ltd., 7th Edition (1) : Mar. 22, 2007 (K)
  • Page 6 LIST OF ABBREVIATIONS ampere(s) pound(s) ABDC after bottom dead center meter(s) alternating current minute(s) ATDC after top dead center newton(s) BBDC before bottom dead center pascal(s) bottom dead center horsepower BTDC before top dead center pound(s) per square inch °C degree(s) Celsius revolution direct current...
  • Page 7: How To Use This Manual

    NOTE maintenance. ○ • This note symbol indicates points of par- Use proper tools and genuine Kawasaki mo- ticular interest for more efficient and con- torcycle parts. Special tools, gauges, and venient operation. testers that are necessary when servicing •...
  • Page 9: Table Of Contents

    GENERAL INFORMATION 1-1 General Information Table of Contents Before Servicing ........................Model Identification......................... General Specifications......................Technical Information......................1-13 Unit Conversion Table ......................1-21...
  • Page 10: Before Servicing

    1-2 GENERAL INFORMATION Before Servicing Before starting to perform an inspection service or carry out a disassembly and reassembly opera- tion on a motorcycle, read the precautions given below. To facilitate actual operations, notes, illustra- tions, photographs, cautions, and detailed descriptions have been included in each chapter wherever necessary.
  • Page 11 GENERAL INFORMATION 1-3 Before Servicing (11) Press When using a press or driver to install a part such as a wheel bearing, apply a small amount of oil to the area where the two parts come in contact to ensure a smooth fit. (12)Ball Bearing and Needle Bearing Do not remove a ball bearing or a needle bearing unless it is absolutely necessary.
  • Page 12 1-4 GENERAL INFORMATION Before Servicing (19)Inspection When parts have been disassembled, visually inspect these parts for the following conditions or other damage. If there is any doubt as to the condition of them, replace them with new ones. Abrasion Crack Hardening Warp Bent...
  • Page 13: Model Identification

    GENERAL INFORMATION 1-5 Model Identification KX125-M1 Left Side View KX125-M1 Right Side View...
  • Page 14 1-6 GENERAL INFORMATION Model Identification KX250-M1 Left Side View KX250-M1 Right Side View...
  • Page 15: General Specifications

    GENERAL INFORMATION 1-7 General Specifications KX125-M2 ∼ M3 KX125M6F ∼ Items KX125-M1 Dimensions Overall Length 2 155 mm (84.8 in.) 2 165 mm (85.2 in.) Overall Width 825 mm (32.5 in.) 840 mm (33.1 in.) 815 mm (32.1 in.) Overall Height 1 200 mm (47.2 in.)
  • Page 16 1-8 GENERAL INFORMATION General Specifications KX125-M2 ∼ M3 KX125M6F ∼ Items KX125-M1 Clutch Type Wet, multi disc ← Transmission: Type 6-speed, constant mesh, return ← shift Gear Ratios: 2.384 (31/13) ← 1.857 (26/14) ← 1.529 (26/17) ← 1.294 (22/17) ←...
  • Page 17 GENERAL INFORMATION 1-9 General Specifications KX125-M2 ∼ M3 KX125M6F ∼ Items KX125-M1 Effective Disc Diameter: Front 220 mm (8.7 in.) 225 mm (8.9 in.) Rear 200 mm (7.9 in.) 215 mm (8.5 in.) Specifications are subject to change without notice, and may not apply to every country.
  • Page 18 1-10 GENERAL INFORMATION General Specifications Items KX250-M1 KX250-M2 Dimensions Overall Length 2 175 mm (85.6 in.) ← Overall Width 825 mm (32.5 in.) 840 mm (33.1 in.) Overall Height 1 205 mm (47.4 in.) 1 265 mm (49.8 in.) Wheelbase 1 480 mm (58.3 in.) ←...
  • Page 19 GENERAL INFORMATION 1-11 General Specifications Items KX250-M1 KX250-M2 Transmission: Type 5 speed, constant mesh, return ← shift Gear Ratios: 1.800 (27/15) ← 1.437 (23/16) ← 1.176 (20/17) ← 1.000 (21/21) ← 0.869 (20/23) ← Final Drive System Type Chain drive ←...
  • Page 20 1-12 GENERAL INFORMATION General Specifications Items KX250-M1 KX250-M2 Effective Disc Diameter: Front 220 mm (8.7 in.) 225 mm (8.9 in.) Rear 200 mm (7.9 in.) 215 mm (8.5 in.) Specifications are subject to change without notice, and may not apply to every country. (EUR): Europe Model...
  • Page 21: Technical Information

    [E]. ○ The mechanism has shorter length between the shift drum and the drive shaft, compared with the previous model (for example, from 67 mm to 43.2 mm for KX125). ○ The shift force is transmitted as follows: Shift Pedal →...
  • Page 22 1-14 GENERAL INFORMATION Technical Information ○ This mechanism operates as follows: 1. Suppose the 1st gear position is set as shown. Neutral Detent [N] 2. Shift Up (for example: shift from 1st to 2nd) (→) : transmitting of shift force The shift pedal is lifted.
  • Page 23 Technical Information Chrome Composite Plating Cylinder (KX250M, KX125M) ○ This new cylinder bore [A] has Kawasaki’s compos- ite cylinder plating, which is used for the first time on two stroke engines. The composite plating includes a nickel-phosphorous alloy, inorganic materials like ce- ramic, silicone carbide and some organic materials.
  • Page 24 1-16 GENERAL INFORMATION Technical Information KIPS (Kawasaki Integrated Power Valve System, KX250M, KX125M) ○ KIPS varies the exhaust port height to broaden the useful rpm range for low end and mid-range without sacrificing the top end power (see ’95 KDX200H Service Manual (Part No. 99924-1181-01) for basic information about KIPS).
  • Page 25 GENERAL INFORMATION 1-17 Technical Information (KX125M) A. Previous KIPS B. New Model C. Full Opened Position D. Low Speed Position E. Straightened Exhaust Passage ○ The KIPS governor is modified so that the exhaust valves operate over a wider rpm range to improve low and mid -range power and smooth the power delivery.
  • Page 26 1-18 GENERAL INFORMATION Technical Information ○ The crescent shaped slide [A] enables the needle to sit closer to the intake ports for quicker throttle response. ○ Large bores in the front and back of the carburetor and a smoother shape (38 to 40 mm-tapered bore [B]) boost mixture flow for more mid-range and top-end power.
  • Page 27 GENERAL INFORMATION 1-19 Technical Information A. Previous Carburetor B. New Carburetor C. Jet Needle D. Air Baffle E. Main Air F. Needle Jet G. Engine Inlet Carburetor (KX125M) ○ The 38 mm (1.496 in.) Mikuni TMX 38-27 carburetor helps boost mid-range and top-end power. ○...
  • Page 28 1-20 GENERAL INFORMATION Technical Information ○ In low range, fuel drops in the fuel/air mixture is larger and tends to stick to the carburetor wall. The arched slide deflects fuel/air mixture flow from the wall to the middle of the carburetor for better atomization and better throttle response.
  • Page 29: Unit Conversion Table

    GENERAL INFORMATION 1-21 Unit Conversion Table Prefixes for Units: Units of Length: × 0.6214 mile Prefix Symbol Power × 3.281 mega × 1 000 000 × 0.03937 kilo × 1 000 centi × 0.01 Units of Torque: milli × 0.001 N·m ×...
  • Page 31: Periodic Maintenance

    PERIODIC MAINTENANCE 2-1 Periodic Maintenance Table of Contents Periodic Maintenance Chart ....................Torque and Locking Agent...................... Specifications ......................... 2-10 Special Tools .......................... 2-13 Periodic Maintenance Procedures..................2-14 Fuel System......................... 2-14 Fuel Hose and Connections Inspection ................2-14 Throttle Cable Inspection ....................2-14 Carburetor Inspection .......................
  • Page 32: Periodic Maintenance

    2-2 PERIODIC MAINTENANCE Brake Fluid Change ......................2-36 Brake Pad Wear Inspection ....................2-37 Brake Master Cylinder Cup and Dust Seal Replacement ..........2-37 Brake Caliper Fluid Seal and Dust Seal Replacement ............. 2-37 Brake Hoses and Connections Inspection ................ 2-38 Brake Hose Replacement ....................
  • Page 33: Periodic Maintenance Chart

    PERIODIC MAINTENANCE 2-3 Periodic Maintenance Chart The maintenance must be done in accordance with this chart to keep the motorcycle in good running condition. FREQUENCY After Every Every Every each 3 races 5 races As re- race or or 7.5 or 12.5 races quired...
  • Page 34 2-4 PERIODIC MAINTENANCE Periodic Maintenance Chart FREQUENCY After Every Every Every each 3 races 5 races As re- race or or 7.5 or 12.5 races quired Page OPERATION 2.5 hr or 25 hr Front fork oil - change 1st time after 2 races, then every 5 races 2-40 Rear shock absorber oil - change 1st time after 2 races, then every 5 races...
  • Page 35: Torque And Locking Agent

    78 in·lb Radiator Bracket Bolts 78 in·lb Engine Top End Main Valve Cover Bolts 52 in·lb Cylinder Head Nuts Spark Plug Engine Mounting Bracket Nuts: Engine Side 10 mm (KX125/250-M1) Engine Side 10 mm (KX125/250-M2 ∼) Frame Side 8 m...
  • Page 36 KX125 KX250 Cylinder Left Cover Bolts (KX250) 52 in·lb Main Lever Mounting Allen Bolt 35 in·lb Governor Shaft Lever Mounting Bolt (KX125) 61 in·lb Exhaust Valve Retaining Bolts (KX125) 52 in·lb Main Shaft Stopper Pin Plug (KX125) 0.08 7 in·lb Main Valve Retaining Bolts (KX250) 52 in·lb...
  • Page 37 Output Shaft Bearing Retaining Screws 0.55 48 in·lb Shift Drum Bearing Retaining Screws (KX125-M1) 0.65 56 in·lb Shift Drum Bearing Retaining Bolts (KX125-M2 ∼) 78 in·lb Shift Drum Bearing Retaining Bolts (KX250) 78 in·lb Drive Shaft Bearing Retaining Bolts (KX250) 78 in·lb Engine Oil Drain Bolt 14.5...
  • Page 38 14.5 Electrical System Flywheel Bolt Flywheel Nut Stator Plate Mounting Screws 0.45 39 in·lb Spark Plug Magneto Cover Bolts: (KX125/250-M1) 43 in·lb Magneto Cover Bolts: KX125/250-M2∼) 35 in·lb C.D.I Unit Mounting Bolts 78 in·lb Ignition Coil Mounting Bolts 78 in·lb...
  • Page 39 PERIODIC MAINTENANCE 2-9 Torque and Locking Agent Basic Torque for General Fasteners Torque Threads dia. (mm) N·m kgf·m ft·lb 3.4 ∼ 4.9 0.35 ∼ 0.50 30 ∼ 43 in·lb 5.9 ∼ 7.8 0.60 ∼ 0.80 52 ∼ 69 in·lb 14 ∼ 19 1.4 ∼...
  • Page 40: Specifications

    1.20 L (1.27 US qt) Engine Top End Cylinder Head Warp – – – 0.03 mm (0.0012 in.) Cylinder, Piston (KX125): 54.010 ∼ 54.025 mm Cylinder Inside Diameter (15 mm 54.10 mm (2.130 in.) (2.1264 ∼ 2.1270 in.) (0.59 in.) below of the cylinder head) 53.955 ∼...
  • Page 41 2 ∼ 3 mm (0.08 ∼ 0.12 in.) Clutch Lever Free Play – – – Friction Plate Thickness 2.72 ∼ 2.88 mm (0.107 ∼ 0.113 in.) KX125 2.6 mm (0.102 in.) 2.92 ∼ 3.08 mm (0.115 ∼ 0.121 in.) KX250 2.8 mm (0.110 in.) Steel Plate Thickness: 1.5 ∼...
  • Page 42 KHL15-10 (KAYABA 01) or equivalent Oil Capacity (par unit): KX125-M1 652 ±4 mL (22.04 ±0.14 US oz.) – – – KX125-M2 ∼ 565 ±4 mL (19.10 ±0.14 US oz.) – – – KX250-M1 664 ±4 mL (22.45 ±0.14 US oz.) –...
  • Page 43: Special Tools

    PERIODIC MAINTENANCE 2-13 Special Tools Steering Stem Nut Wrench: Fork Piston Rod Puller, M12 × 1.25: 57001-1100 57001-1289 Jack: Fork Oil Level Gauge: 57001-1238 57001-1290...
  • Page 44: Periodic Maintenance Procedures

    2-14 PERIODIC MAINTENANCE Periodic Maintenance Procedures Fuel System Fuel Hose and Connections Inspection ○ The fuel hoses are designed to be used throughout the motorcycle’s life without any maintenance, however, if the motorcycle is not properly handled, the inside the fuel line can cause fuel to leak [A] or the hose to burst.
  • Page 45: Carburetor Inspection

    PERIODIC MAINTENANCE 2-15 Periodic Maintenance Procedures If the throttle grip free play cannot be adjusted with the adjuster at the upper end of the throttle cable, use the cable adjuster [A] at the carburetor. • Free the fuel cut valve connector from the frame. •...
  • Page 46: Fuel Tank And Tap Cleaning

    2-16 PERIODIC MAINTENANCE Periodic Maintenance Procedures WARNING Clean the element in a well-ventilated area, and take care that there are no sparks or flame anywhere near the working area; this includes any appliance with a pilot light. Because of the danger of highly flammable liquids, do not use gasoline or a low flash-point solvent to clean the element.
  • Page 47: Coolant Inspection

    Water and coolant mixture ratio: 1:1 (water 50 %, Coolant 50 %) Total amount: KX125: 0.97 L (1.02 US qt.) KX250: 1.20 L (1.27 US qt.) Coolant Deterioration Inspection • Visually inspect the coolant.
  • Page 48 Then push down and turn it further in the same direction and remove the cap. • Place a container under the coolant drain plug (KX125) [A] or plugs (KX250) [B], and drain the coolant from the radiator and engine by removing the drain plug on the water pump cover and the cylinder (KX250).
  • Page 49: Water Hoses And Connections Inspection

    PERIODIC MAINTENANCE 2-19 Periodic Maintenance Procedures • Fill the radiator up to the bottom of the radiator filler neck [B] with coolant [A], and install the cap, turning it clockwise about 1/4 turn. NOTE ○ Pour in the coolant slowly so that it can expel the air from the engine and radiator.
  • Page 50: Cylinder Wear Inspection

    Piston Diameter Measurement • Measure the outside diameter of the piston 15.0 mm (0.59 in.) (KX125) or 20.5 mm (0.81 in.) (KX250) [A] up from the bottom of the piston at a right angle to the direction of the piston pin.
  • Page 51: Piston/cylinder Clearance Inspection

    Measure the piston diameter as just described, and measure the cylinder diameter at the very bottom of the cylinder. Piston/Cylinder Clearance Standard: KX125: 0.040 ∼ 0.070 mm (0.0016 ∼ 0.0028 in.) KX250: 0.049 ∼ 0.079 mm (0.0023 ∼ 0.0031 in.)
  • Page 52: Piston Ring, Piston Ring Groove Inspection

    If the ring has worn down to less than the service limit, replace the ring; if the groove width exceeds the service limit, replace the piston. Piston Ring/Groove Clearance KX125: 0.015 ∼ 0.050 mm (0.0006 ∼ 0.0020 in.) Standard: Service Limit: 0.15 mm (0.0059 in.) KX250: 0.025 ∼...
  • Page 53: Piston Ring End Gap Inspection

    [C] If the gap is wider than the service limit, the ring is over- worn and must be replaced. Piston Ring End Gap KX125: 0.35 ∼ 0.55 mm (0.0138 ∼ 0.0217 in.) Standard: Service Limit: 0.85 mm (0.033 in.) KX250: 0.25 ∼...
  • Page 54: Exhaust Valve Cleaning And Inspection

    2-24 PERIODIC MAINTENANCE Periodic Maintenance Procedures Piston Pin Diameter KX125 14.995 ∼15.000 mm (0.5904 ∼ 0.5906 Standard: in.) Service Limit: 14.96 mm (0.589 in.) KX250 17.995 ∼18.000 mm (0.7085 ∼ 0.7087 Standard: in.) Service Limit: 17.96 mm (0.707 in.) Piston Pin Hole Diameter KX125 15.001 ∼...
  • Page 55: Muffler Baffle Change

    PERIODIC MAINTENANCE 2-25 Periodic Maintenance Procedures Muffler Baffle Change • Remove the muffler body. • Remove the muffler pipe mounting bolts [A], and pull the muffler pipe [B] from the muffler body. • Unscrew the inner pipe bolts [A]. • Pull the inner pipe [B] from the muffler body.
  • Page 56: Clutch Plates Inspection

    Measure the thickness [A] of the friction plates [B] and steel plates with vernier calipers. If they have worn past the service limit, replace them with new ones. Friction Plate Thickness KX125: 2.72 ∼ 2.88 mm (0.107 ∼ 0.113 in.) Standard: Service Limit: 2.6 mm (0.102 in.) KX250: 2.92 ∼...
  • Page 57: Engine Bottom End/transmission

    PERIODIC MAINTENANCE 2-27 Periodic Maintenance Procedures Friction and Steel Plate Warp Inspection • Place each friction plate or steel plate on a surface plate, and measure the gap between the surface plate [A] and each friction plate or steel plate [B] with a thickness gauge [C].
  • Page 58: Wheels/tires

    API SE, SF or SG API SH, SJ or SL with JASO MA Viscosity SAE10W-40 Capacity KX125: 0.7 L (0.74 US qt.) KX250: 0.85 L (0.90 US qt.) NOTE ○ Although 10W-40 engine oil is the recommended oil for most conditions, the oil viscosity may need to be changed to accommodate atmospheric conditions in your riding area.
  • Page 59: Tires Inspection

    Check and balance the wheel when a tire is replaced with a new one. Standard Tire KX125 Front: Size: 80/100-21 51M Make: DUNLOP Type: (KX125-M1 ∼ M2) D739FA, Tube (EUR) D755FJ, Tube (KX125-M3 ∼) D742F, Tube (EUR) D755FJ, Tube Rear: Size: 100/90-19 57M Make:...
  • Page 60: Spoke Tightness Inspection

    2-30 PERIODIC MAINTENANCE Periodic Maintenance Procedures Spoke Tightness Inspection • Inspect that all the spokes are tightened evenly. If spoke tightness is uneven or loose, tighten the spoke nipples evenly. Torque - Spoke Nipples: 2.2 N·m (0.22 kgf·m, 19 in·lb) •...
  • Page 61: Final Drive

    PERIODIC MAINTENANCE 2-31 Periodic Maintenance Procedures Final Drive Drive Chain Inspection Drive Chain Slack Inspection • Raise the rear wheel off the ground, rotate the rear wheel to find the place where the chain is tightest (because it wears unevenly). Special Tool - Jack: 57001-1238 •...
  • Page 62: Drive Chain Wear Inspection

    2-32 PERIODIC MAINTENANCE Periodic Maintenance Procedures NOTE ○ When inserting the cotter pin, if the slots in the nut do not align with the cotter pin hole in the axle shaft, tighten the nut clockwise [A] up to next alignment. ○...
  • Page 63: Drive Chain Lubrication

    Standard Chain Make: DAIDO Type: D.I.D 520DMA2 Link: KX125-M1 112 Links KX125-M2 ∼ 114 Links KX250 114 Links Drive Chain Lubrication • If the chain appears especially dirty, it should be cleaned before lubrication with high flash-point solvent. •...
  • Page 64: Rear Sprocket Warp (runout) Inspection

    2-34 PERIODIC MAINTENANCE Periodic Maintenance Procedures Rear Sprocket Warp (Runout) Inspection • Using the jack, raise the rear wheel off the ground. Special Tool - Jack: 57001-1238 • Set a dial gauge [A] against the rear sprocket [B] near the teeth as shown and rotate [C] the rear wheel to measure the sprocket runout (warp).
  • Page 65: Brake Fluid Level Inspection

    PERIODIC MAINTENANCE 2-35 Periodic Maintenance Procedures Brake Fluid Level Inspection In accordance with the Periodic Maintenance Chart, in- spect the brake fluid level in the front or rear brake fluid reservoirs. • Check the brake fluid level in the front or rear brake reser- voir [A].
  • Page 66: Brake Fluid Change

    Remove the rubber cap [A] on the bleed valve [B]. • Attach a clear plastic hose to the bleed valve on the caliper, and run the other end of the hose into a con- tainer. • For KX125/250-M2 model∼; as shown in the figure.
  • Page 67: Brake Pad Wear Inspection

    PERIODIC MAINTENANCE 2-37 Periodic Maintenance Procedures • Change the brake fluid as follows: ○ Repeat this operation until fresh brake fluid comes out from the plastic hose or the color of the fluid changes. 1. Open the bleed valve [A] 2.
  • Page 68: Brake Hoses And Connections Inspection

    2-38 PERIODIC MAINTENANCE Periodic Maintenance Procedures Brake Hoses and Connections Inspection • Inspect the brake hose and fittings for deterioration, cracks and signs of leakage. ○ The high pressure inside the brake line can cause fluid to leak [A] or the hose to burst if the line is not properly main- tained.
  • Page 69: Suspension

    CAUTION If the inner tube is badly bent or creased, replace Excessive bending, followed by subsequent straightening, can weaken the inner tube. • For KX125/250-M2 model ∼; as shown in the figure.
  • Page 70: Front Fork Oil Change/oil Level Adjustment (each Fork Leg)

    ○ For KX125/250-M1 model, pull the fork spring [A] away from the top plug a little and slip the spanner wrench [B] in on top of the spring seat and under the push rod nut [C].
  • Page 71 • Fill the specified oil to the outer tube. Recommended Oil KHL15-10 (KAYABA 01) or equivalent Front Fork Oil Capacity KX125-M1: 652 ±4 mL (22.04 ±0.14 US oz) KX125-M2∼: 565 ±4 mL (19.10 ±0.14 US oz) KX250-M1: 664 ±4 mL (22.45 ±0.14 US oz) KX250-M2∼:...
  • Page 72: Rear Shock Absorber Oil Change

    Special Tool - Fork Oil Level Gauge: 57001-1290 Oil Level (fully compressed, without spring) Standard 133 ∼ 137 mm (5.24 ∼ 5.39 in.) KX125-M1: 103 ∼ 107 mm (4.06 ∼ 4.21 in.) KX125-M2∼: 123 ∼ 127 mm (4.84 ∼ 5.00 in.) KX250-M1: 86 ∼...
  • Page 73: Chain Guide Wear Inspection

    Feel for steering looseness by pushing and pulling the forks. If you feel looseness, adjust the steering. • For KX125/250-M2 model ∼; as shown in the figure. Steering Play Adjustment • Using the jack, raise the front wheel off the ground.
  • Page 74 2-44 PERIODIC MAINTENANCE Periodic Maintenance Procedures KX125-M1 ∼ M3/KX250-M1 ∼ M2; • Slide the holder belt [A] out off. • Remove number plate bolt [B] and number plate [C]. • Remove: Handlebar Holder Bolts [A] Handlebar Holder [B] Handle Bar [C] KX125M6F ∼;...
  • Page 75 • Check the steering again. If the steering is too tight or too loose, repeat the adjust- ment as mentioned above. KX125-M1 ∼ M3/KX250-M1 ∼ M2; • Install the handlebar [A] on the handlebar holder as shown. Same Length [B] Bridge Bar [C] •...
  • Page 76: Steering Stem Bearing Lubrication

    2-46 PERIODIC MAINTENANCE Periodic Maintenance Procedures KX125M6F ∼; • Install the handlebar [A] on the handlebar holder as shown. Same Length [B] Bridge Bar [C] Protrusion of Graduation [D] • Install the handlebar holders [A] with handlebar. ○ Tighten the front and rear bolts [B] of the handlebar hold- ers equally.
  • Page 77: Electrical System

    PERIODIC MAINTENANCE 2-47 Periodic Maintenance Procedures Electrical System Spark Plug Cleaning and Inspection • Remove the spark plug, and visually inspect it. • Clean the spark plug, preferably in a sandblasting device, and then clean off any abrasive particles. The plug may also be cleaned using a high-flash point solvent and a wire brush or other suitable tool.
  • Page 78: General Lubrication

    2-48 PERIODIC MAINTENANCE Periodic Maintenance Procedures General Lubrication Lubrication • Before lubricating each part, clean off any rusty spots with rust remover and wipe off any grease, oil, dirt, or grime. • Lubricate the points listed below with indicated lubricant. NOTE ○...
  • Page 79: Nut, Bolt, And Fastener Tightness

    PERIODIC MAINTENANCE 2-49 Periodic Maintenance Procedures Nut, Bolt, and Fastener Tightness Tightness Inspection • Inspect the tightness of bolts and nuts listed here. Also, check to see that each cotter pin is in place and in good condition. NOTE ○ For the engine fasteners, check the tightness of them when the engine is cold (at room temperature).
  • Page 81 FUEL SYSTEM 3-1 Fuel System Table of Contents Exploded View........................Specifications ......................... Special Tools .......................... Throttle Grip and Cable ......................3-10 Free Play Inspection ......................3-10 Free Play Adjustment......................3-10 Throttle Cable Installation ....................3-10 Throttle Cable Lubrication....................3-10 Throttle Cable Inspection ....................3-10 Carburetor ..........................
  • Page 82: Exploded View

    3-2 FUEL SYSTEM Exploded View KX125M:...
  • Page 83: N·m

    15. Air Screw 16. Slow Jet 17. Main Jet 18. Needle Jet 19. Main Jet Holder 20. Float Valve Needle 21. Float 22. Carburetor Holder 23a. Reed Valve (KX125-M1 Model) 23b. Reed Valve (KX125-M2 Model∼) G: Apply grease. O: Apply oil.
  • Page 84 3-4 FUEL SYSTEM Exploded View KX250M:...
  • Page 85: Carburetor Top Cover Allen Bolts (kx250)

    FUEL SYSTEM 3-5 Exploded View Torque Fastener Remarks N·m kgf·m ft·lb Carburetor Holder Mounting Bolts 78 in·lb Carburetor Holding Clamp Screw 0.15 13 in·lb Reed Valve Screws 9 in·lb Throttle Sensor Bolt 17 in·lb Carburetor Top Cover Allen Bolts 35 in·lb 6.
  • Page 86 3-6 FUEL SYSTEM Exploded View...
  • Page 87: Rear Frame Mounting Bolts

    FUEL SYSTEM 3-7 Exploded View Torque Fastener Remarks N·m kgf·m ft·lb Rear Frame Mounting Bolts Air Cleaner Duct Clamp Screw 0.15 13 in·lb Fuel Tap Plate Mounting Screws 0.08 7 in·lb Air Cleaner Duct Nuts 26 in·lb Air Cleaner Housing Bolts 78 in·lb 6.
  • Page 88: Specifications

    3-8 FUEL SYSTEM Specifications KX125: Standard Item Service Limit KX125-M3 ∼ KX125-M1 KX125-M2 Carburetor Make/Type MIKUNI TMX38 – – – Main Jet: #420 – – – Throttle Valve Cutaway #5.75 – – – Jet Needle 6CHJ 11-82 6CHJ 10-82 – – –...
  • Page 89: Special Tools

    FUEL SYSTEM 3-9 Special Tools Fuel Level Gauge, M18 × 1.0: Graduated Cylinder & Tube: 57001-122 57001-1584 Fuel Level Gauge: 57001-1577...
  • Page 90: Throttle Grip And Cable

    3-10 FUEL SYSTEM Throttle Grip and Cable If the throttle grip has excessive free play due to cable stretch or misadjustment, there will be a delay in throttle re- sponse. Also, the throttle valve may not open fully at full throttle.
  • Page 91: Carburetor

    Remove the drain plug from the bottom of the float bowl, and screw a fuel level gauge [A] into the plug hole. Special Tools - Fuel Level Gauge: 57001-1577 (KX125) Graduated Cylinder & Tube: 57001-1584 Fuel Level Gauge, M18 × 1.0: 57001-122 (KX250) •...
  • Page 92: Service Fuel Level Adjustment

    Service Fuel Level (above the bottom edge of the carb. body) Standard: 10 ±1 mm (0.394 ±0.039 in.) (KX125) 10.5 ±1 mm (0.413 ±0.039 in.) (KX250) If the fuel level is incorrect, adjust it. • Turn the fuel tap to the OFF position and remove the fuel level gauge.
  • Page 93 Increasing the float height lowers the fuel level and decreasing the float height raises the fuel level. Float Height Standard: 9.5 ±1 mm (0.374 ±0.039 in.) (KX125) 6.5 ±1 mm (0.256 ±0.039 in.) (KX250) NOTE ○ Float height [A] is the distance from the float bowl mat- ing surface [B] of the carburetor body (with the gasket removed) to the top of the float [C].
  • Page 94: Carburetor Removal

    • Drain the fuel from the float bowl by removing the drain plug. After draining, install the drain plug securely. • Unscrew the carburetor cap screws (KX125) or bolts (KX250) [A].
  • Page 95: Carburetor Installation

    • Tighten: Torque - Carburetor Top Cover Screws: 3.0 N·m (0.3 kgf·m, 26 in·lb) (KX125) Carburetor Top Cover Allen Bolts: 3.9 N·m (0.4 kgf·m, 35 in·lb) (KX250) • When installing the carburetor into the carburetor holder, align the center [A] of the carburetor with the groove [B] on the holder.
  • Page 96: Fuel Inspection

    Install the drain plug on the float bowl, and tighten it se- curely. • Install the carburetor. Carburetor Disassembly • Remove the carburetor. • Unscrew the carburetor top cap screws (KX125) or bolts (KX250) [A]. • Pull out the throttle valve assembly.
  • Page 97 FUEL SYSTEM 3-17 Carburetor • Remove the throttle valve assembly [A], spring [B], re- tainer [C] and carburetor cap from the carburetor cable lower end. • Disassemble the throttle valve assembly; connector [A], jet needle with circlip [B] and throttle valve [C]. •...
  • Page 98 3-18 FUEL SYSTEM Carburetor (For KX250) • Remove the throttle sensor link assembly screws [A]. • Remove the link assembly [B]. KX125: • Remove the following parts from the carburetor body. A. Idle Adjusting Screw B. Nut C. Air Screw D. Spring E.
  • Page 99: Carburetor Assembly

    FUEL SYSTEM 3-19 Carburetor Carburetor Assembly • Clean the disassembly parts before assembling. • Replace the O-rings with a new one if it is deteriorated or damaged. • Turn in the air screw [A] fully but not tightly, and then back it out the specified number of turns.
  • Page 100: Carburetor Inspection

    3-20 FUEL SYSTEM Carburetor Carburetor Inspection WARNING Gasoline is extremely flammable and can be ex- plosive under certain conditions. Always stop the engine and do not smoke. Make sure the area is well-ventilated and free from any source of flame or sparks;...
  • Page 101 FUEL SYSTEM 3-21 Carburetor • Remove the slow jet. • Inspect the slow jet for any damage. If the slow jet is damaged, replace it with a new one. • Remove the throttle valve and jet needle. • Inspect the outside of the throttle valve for scratches and abnormal wear.
  • Page 102: Air Cleaner

    3-22 FUEL SYSTEM Air Cleaner Housing Removal • Remove: Side Covers Seat Muffler (see Engine Top End chapter) Bolts and Rear Fender [A] Screws and Rear Flap [B] Rear Frame Mounting Bolts [C] • Loosen the air cleaner duct clamp [D]. •...
  • Page 103: Element Cleaning And Inspection

    FUEL SYSTEM 3-23 Air Cleaner • Install the element so that its tab [A] faces upward and fit the element projections [B] to the holes of the housing [C]. Element Cleaning and Inspection • Refer to the Air Cleaner Element Cleaning and Inspection in the Periodic Maintenance chapter.
  • Page 104: Fuel Tank

    3-24 FUEL SYSTEM Fuel Tank Fuel Tank Removal WARNING Gasoline is extremely flammable and can be ex- plosive under certain conditions. Always stop the engine and do not smoke. Make sure the area is well-ventilated and free from any source of flame or sparks;...
  • Page 105: Fuel Tap Inspection

    FUEL SYSTEM 3-25 Fuel Tank Fuel Tap Inspection • Remove the fuel tap. • Check the fuel tap filter screen [A] for any breaks or dete- rioration. If the fuel tap screen have any breaks or is deteriorated, it may allow dirt to reach the carburetor, causing poor run- ning.
  • Page 106: Reed Valve

    ○ Take off the reed valve [A] out of the cylinder. Reed Valve Installation • For KX125, install the reed valve [A] as shown. Upward [B] • For KX250, install the reed valve [A] so that the ”↑” marked side [B] faces upward.
  • Page 107: Reed Valve Inspection

    FUEL SYSTEM 3-27 Reed Valve Reed Valve Inspection • Inspect the reeds for cracks, folds, or other visible dam- age. If there is any doubt as to the condition of a reed, replace the reed valve part with a new one. If a reed becomes wavy, replace the valve part with a new one even if its warp is less than the service limit.
  • Page 109 COOLING SYSTEM 4-1 Cooling System Table of Contents Exploded View........................Specifications ......................... Special Tool ..........................Coolant ........................... Coolant Level Inspection....................Coolant Deterioration Inspection..................Coolant Draining ....................... Coolant Filling ........................Air Bleeding........................Cooling System Pressure Testing ..................Cooling System Flushing ....................Disassembly and Assembly Precautions................
  • Page 110: Exploded View

    4-2 COOLING SYSTEM Exploded View KX125:...
  • Page 111: Water Pump Cover Bolts

    COOLING SYSTEM 4-3 Exploded View Torque Fastener Remarks N·m kgf·m ft·lb Water Pump Cover Bolts 78 in·lb Coolant Drain Bolt (Water Pump Cover) 78 in·lb Water Pump Impeller Bolt 61 in·lb Right Engine Cover Bolts 78 in·lb Radiator Shroud Bolts 78 in·lb Radiator Mounting Bolts 78 in·lb...
  • Page 112 4-4 COOLING SYSTEM Exploded View KX250:...
  • Page 113: Coolant Drain Bolt (cylinder) (kx250)

    COOLING SYSTEM 4-5 Exploded View Torque Fastener Remarks N·m kgf·m ft·lb Water Pump Cover Bolts 78 in·lb Water Pump Cover Fitting Bolts 52 in·lb Coolant Drain Bolt (Water Pump Cover) 78 in·lb Water Pump Impeller Bolt 61 in·lb Right Engine Cover Bolts 78 in·lb Coolant Drain Plug (Cylinder) 78 in·lb...
  • Page 114: Specifications

    Permanent type antifreeze for aluminum engines and radiators Color Green Mixed Ratio Soft water 50%, antifreeze 50% Total Amount: KX125 0.97 L (1.02 US qt.) KX250 1.20 L (1.27 US qt.) Radiator 93 ∼ 123 kPa (0.95 ∼ 1.25 kgf/cm², 13 ∼ 18 psi)
  • Page 115: Special Tool

    COOLING SYSTEM 4-7 Special Tool Bearing Driver Set: 57001-1129...
  • Page 116: Coolant

    4-8 COOLING SYSTEM Coolant Check the coolant level each day before riding the motor- cycle, and replenish coolant if the level is low. Change the coolant in accordance with the Periodic Maintenance Chart (see Periodic Maintenance chapter). WARNING To avoid burns, do not remove the radiator cap or try to inspect the coolant level or change the coolant when the engine is still hot.
  • Page 117: Cooling System Flushing

    COOLING SYSTEM 4-9 Coolant Cooling System Flushing Over a period of time, the cooling system accumulates rust, scale, and lime in the water jacket and radiator. When this accumulation is suspected or observed, flush the cool- ing system. If this accumulation is not removed, it will clog up the water passages and considerably reduce the effi- ciency of the cooling system.
  • Page 118: Disassembly And Assembly Precautions

    4-10 COOLING SYSTEM Disassembly and Assembly Precautions • Prior to disassembly of cooling system parts (radiator, pump, etc), wait until the coolant cools down, and then drain the coolant. • After assembling and filling the system with coolant, bleed any air from the system.
  • Page 119: Water Pump

    COOLING SYSTEM 4-11 Water Pump Water Pump Cover Removal • Drain the coolant (see Coolant Draining). • Loosen the water hose clamps [A], and disconnect the water hoses on the water pump cover [B]. • Unscrew the cover bolts [C], and remove the water pump cover.
  • Page 120: Impeller Inspection

    4-12 COOLING SYSTEM Water Pump Impeller Inspection • Visually check the impeller [A]. If the surface is corroded, or if the blades [B] are dam- aged, replace the impeller. Water Pump Shaft Removal • Remove: Right Engine Cover (see Right Engine Cover Removal in the Engine Right Side chapter) •...
  • Page 121: Oil Seal Installation

    COOLING SYSTEM 4-13 Water Pump • Insert a bar [A] into the water pump shaft hole from the inside of the right engine cover, and remove the oil seal [B] by tapping [C] evenly around the seal lips. Oil Seal Installation CAUTION If the oil seal or ball bearing is removed, replace all of them with new ones at the same time...
  • Page 122: Radiator Shroud Bolts

    Unscrew the bolts [A]. • Remove: Radiator Brackets [B] Radiator [C] with the cooling hoses ○ For KX125 be sure to remove the magneto lead (harness) from left radiator. Radiator Installation • Radiator installation is the reverse of removal. •...
  • Page 123: Radiator Inspection

    COOLING SYSTEM 4-15 Radiator Radiator Inspection • Check the radiator core. If there are obstructions to air flow, remove them. If the corrugated fins are deformed, carefully straighten them with the thin blade of a screwdriver [A]. CAUTION Do not tear the radiator tubes while straightening the fins.
  • Page 124: Cap Inspection

    4-16 COOLING SYSTEM Radiator Cap Inspection • Inspect the condition of the valve spring [B], and the top and bottom valve seals [A] of the radiator cap. If any one of them shows visible damage, replace the cap. • Wet the top and bottom valve seals with water or coolant to prevent pressure leaks.
  • Page 125 Piston Ring End Gap Inspection ..................5-14 Piston, Piston Pin, Connecting Rod Wear Inspection ............5-14 Exhaust Valve (KIPS) ......................5-15 Exhaust Valve Removal (KX125 Model) ................5-15 Exhaust Valve Removal (KX250 Model) ................5-16 Exhaust Valve Installation (KX125 Model) ................ 5-17 Exhaust Valve Installation (KX250 Model) ................
  • Page 126: Exploded View

    5-2 ENGINE TOP END Exploded View KX125:...
  • Page 127: Main Valve Cover Bolts

    31. Governor Shaft Lever 32. Exhaust Valve Right (Identification Slot) 33. Exhaust Valve Left 34a. Expansion Chamber (KX125-M1 model) 34b. Expansion Chamber (KX125-M2 model ∼) 35. Rubber Seals 36. Muffler Body G: Apply grease. L: Apply a non-permanent locking agent.
  • Page 128: Kx250

    5-4 ENGINE TOP END Exploded View KX250:...
  • Page 129: Cylinder Left Cover Bolts (kx250)

    ENGINE TOP END 5-5 Exploded View Torque Fastener Remarks N·m kgf·m ft·lb Cylinder Head Nuts Spark Plug Main Valve Cover Bolts 52 in·lb Main Valve Retaining Bolts 52 in·lb Main Valve Rod Cover Screw 52 in·lb Main Lever Mounting Allen Bolt 35 in·lb Operating Rod Retaining Screw 0.55...
  • Page 130: Specifications

    5-6 ENGINE TOP END Specifications KX125: Item Standard Service Limit Cylinder Head Cylinder Compression (Usable range) – – – 890 ∼ 1 370 kPa (9.1 ∼ 14.0 kgf/cm², 129 ∼ 199 psi) Cylinder Head Warp – – – 0.03 mm (0.0012 in.) Cylinder, Piston 54.010 ∼...
  • Page 131: Special Tools

    ENGINE TOP END 5-7 Special Tools Compression Gauge, 20 kgf/cm²: Compression Gauge Adapter, M14 × 1.25: 57001-221 57001-1159 Piston Pin Puller Assembly: 57001-910...
  • Page 132: Cylinder Head

    Cylinder Compression Usable Range: 890 ∼ 1 370 kPa (9.1 ∼ 14.0 kgf/cm², 129 ∼ KX125 199 psi) 825 ∼ 1 275 kPa (8.4 ∼ 13.0 kgf/cm², 119 ∼ KX250 185 psi)
  • Page 133: Cylinder Head Installation

    Check for a crust of minerals and rust in the head water jacket, and remove them if necessary. • For KX125, install new O-rings to the grooves of the cylin- der securely. • For KX250, install a new cylinder head gasket with the EX marked side [A] forward.
  • Page 134: Cylinder

    Remove the KIPS cover [A] at the cylinder. • Remove the governor shaft lever in accordance with the following procedure . KX125 ○ Remove the bolt [A] and pull out the governor shaft lever [B] from the main shaft. KX250 ○...
  • Page 135: Cylinder Installation

    Torque - Governor Shaft Lever Mounting Bolt: 6.9 N·m (0.7 kgf·m, 61 in·lb) • Install the KIPS cover. • Tighten: Torque - KIPS Cover Bolts: KX125-M1: 4.9 N·m (0.5 kgf·m, 43 in·lb) KX125-M2 ∼: 8.8 N·m (0.9 kgf·m, 78 in·lb)
  • Page 136: Piston Removal

    5-12 ENGINE TOP END Cylinder KX250 • Install the governor shaft lever and operating rod collar in accordance with the following procedure. ○ Put a 9 mm (0.35 in.) spanner [A] wrench on the governor shaft lever upper end. ○ Turn the governor shaft lever counterclockwise with the wrench and fit the groove of the operating rod collar [B] to the boss of the governor shaft lever, and install the collar...
  • Page 137: Cylinder Wear Inspection

    ○ For KX125, the piston ring have a “R” mark [A] on it upper surface. ○ Install the ring so that the pin [A] in the piston ring groove is between the ends of the piston ring.
  • Page 138: Piston Diameter Measurement

    5-14 ENGINE TOP END Cylinder Piston Diameter Measurement • Refer to the Piston Diameter Measurement in the Periodic Maintenance chapter. Piston/Cylinder Clearance • Refer to the Piston/Cylinder Clearance Inspection in the Periodic Maintenance chapter. Piston Ring, Piston Ring Groove Inspection •...
  • Page 139: Exhaust Valve (kips)

    ENGINE TOP END 5-15 Exhaust Valve (KIPS) Exhaust Valve Removal (KX125 Model) • Drain the coolant. • Remove: Radiator (see Radiator Removal in the Cooling System chapter) Muffler (see Muffler Removal) KIPS Cover (see Right Engine Cover Removal in the...
  • Page 140: Exhaust Valve Removal (kx250 Model)

    5-16 ENGINE TOP END Exhaust Valve (KIPS) Exhaust Valve Removal (KX250 Model) • Remove: Carburetor (see Carburetor Removal in the Fuel System chapter) Cylinder Head (see Cylinder Head Removal) • Remove the KIPS cover at the cylinder • Remove the E-clip [A] and operating rod collar [B] from the operating rod.
  • Page 141: Exhaust Valve Installation (kx125 Model)

    • Unscrew the two main valve retaining bolts [A] and take out the main exhaust valve assembly [B] from the cylinder. Exhaust Valve Installation (KX125 Model) • Scrape out any carbon and clean the valves with a high flash-point solvent.
  • Page 142 5-18 ENGINE TOP END Exhaust Valve (KIPS) • Fit the spring [A] to the main lever [B]. • Insert the main shaft [A] in the hole of the cylinder and through the holes in the main lever [B] with spring [C]. •...
  • Page 143: Exhaust Valve Installation (kx250 Model)

    Install the KIPS cover. • Tighten: Torque - KIPS Cover Bolts: KX125-M1: 4.9 N·m (0.5 kgf·m, 43 in·lb) KX125-M2 ∼: 8.8 N·m (0.9 kgf·m, 78 in·lb) • Install the removal parts. Exhaust Valve Installation (KX250 Model) • Remove any carbon and clean the valves with a high flash -point solvent.
  • Page 144 5-20 ENGINE TOP END Exhaust Valve (KIPS) • For KX250-M2 model∼; note the following. ○ Apply a 2-stroke engine oil to the main exhaust valve [A]. • Insert the main exhaust valve assembly [A] into the cylin- der [B]. • Install the main valve retaining bolts [C] securely and tighten them.
  • Page 145 ENGINE TOP END 5-21 Exhaust Valve (KIPS) • Align the punch mark [A] on the main shaft gear with the groove [B] on the main valve rod. • Turn the cylinder upside down. • Push [A] the main valve rod in until it is fully seated into the cylinder.
  • Page 146 5-22 ENGINE TOP END Exhaust Valve (KIPS) • Insert the idle gear. • Apply high temperature grease to the O-ring. • Mount the valve guides [B, D] on the sub exhaust valves [A] and idle gear [C]. • Apply a non-permanent locking agent to the Allen bolt. •...
  • Page 147 ENGINE TOP END 5-23 Exhaust Valve (KIPS) ○ The distance from the top of the operating rod collar to the cylinder should be 14.5 ∼ 15.5 mm (0.57 ∼ 0.61 in.) [A]. ○ In the fully open position with the main valve rod flush with the cylinder [A], the sub exhaust valves will be aligned [B] with the sub exhaust ports.
  • Page 148: Muffler (expansion Chamber, Muffler Body)

    • Remove the O-rings from the expansion chamber. ○ For KX250: be sure to remove exhaust gasket. • For KX125/250-M2 model∼; as shown in the figure. Muffler Installation • Scrape any carbon out of the expansion chamber. • Check the exhaust O-rings for signs of damage.
  • Page 149 ENGINE RIGHT SIDE 6-1 Engine Right Side Table of Contents Exploded View........................Specifications ......................... Special Tools .......................... Clutch Cable ........................... Clutch Lever Free Play Check ..................Free Play Adjustment......................Clutch Cable Removal ...................... Clutch Cable Installation ....................Clutch Cable Lubrication and Inspection ................Clutch Cover...........................
  • Page 150: Exploded View

    6-2 ENGINE RIGHT SIDE Exploded View KX125:...
  • Page 151: Engine Right Side

    37. Clutch Pressure Plate EO: Apply engine oil. G: Apply high temperature grease. L: Apply a non-permanent locking agent to the threads. M: Apply molybdenum disulfide grease O: Apply oil. Si: Apply silicone grease. A: KX125-M1 ∼ M3 Model B: KX125M6F Model ∼...
  • Page 152 6-4 ENGINE RIGHT SIDE Exploded View KX250:...
  • Page 153: Right Engine Cover Bolts

    ENGINE RIGHT SIDE 6-5 Exploded View Torque Fastener Remarks N·m kgf·m ft·lb Clutch Cover Bolts 78 in·lb Right Engine Cover Bolts 78 in·lb Oil Filler Cap 0.15 13 in·lb Governor Shaft Lever Positioning Plug 0.06 5 in·lb Exhaust Valve Advancer Lever Mounting Allen Bolt 35 in·lb Gear Set Lever Nut 78 in·lb...
  • Page 154: Kx125 Kx250

    2 ∼ 3 mm (0.08 ∼ 0.12 in.) Lever Free Play – – – Friction Plate Thickness 2.72 ∼ 2.88 mm (0.107 ∼ 0.113 in.) KX125 2.6 mm (0.102 in.) 2.92 ∼ 3.08 mm (0.115 ∼ 0.121 in.) KX250 2.8 mm (0.110 in.) Steel Plate Thickness: 1.5 ∼...
  • Page 155: Special Tools

    ENGINE RIGHT SIDE 6-7 Special Tools Outside Circlip Pliers: Flywheel Holder: 57001-144 57001-1313 Clutch Holder: Flywheel & Pulley Holder: 57001-1243 57001-1605...
  • Page 156: Clutch Cable

    Line up the slots [C] in the clutch lever, knurled locknut, and adjuster, and then free the cable from the clutch lever. ○ For KX125, remove the magneto cover (see Release Shaft Removal). • Free the clutch inner cable tip from the clutch release lever.
  • Page 157: Clutch Cover

    ENGINE RIGHT SIDE 6-9 Clutch Cover Clutch Cover Removal • Drain the engine oil (see Transmission Oil Change in the Periodic Maintenance chapter). • Remove the brake pedal (see Brake Pedal Removal in the Brake chapter). • Unbolt the clutch cover bolts [A], and take off the clutch cover [B].
  • Page 158: Right Engine Cover

    [B] from the right side of the cylinder. • Remove the governor shaft lever in accordance with the following procedure. KX125 ○ Remove the bolt [A] and pull out the governor shaft lever [B] from the main shaft. KX250 ○...
  • Page 159: Right Engine Cover Installation

    Torque - Governor Shaft Lever Mounting Bolt [C]: 6.9 N·m (0.7 kgf·m, 61 in·lb) • Install the KIPS cover. • Tighten: Torque - KIPS Cover Bolts: KX125-M1: 4.9 N·m (0.5 kgf·m, 43 in·lb) KX125-M2 ∼: 8.8 N·m (0.9 kgf·m, 78 in·lb)
  • Page 160: Right Engine Cover Disassembly

    6-12 ENGINE RIGHT SIDE Right Engine Cover KX250 • Put a 9 mm (0.35 in.) spanner wrench [A] on the governor shaft lever upper end. • Turn the governor shaft lever counterclockwise with the wrench and fit the groove of the operating rod collar [B] to the boss of the governor shaft lever, and install the collar on the operating rod while turning the governor shaft lever clockwise.
  • Page 161: Exhaust Advancer Assembly Disassembly/assembly

    ENGINE RIGHT SIDE 6-13 Right Engine Cover • Remove the plug screw [A] and take out the governor shaft lever positioning pin. • Pull the governor shaft lever [B] out of the right engine cover. • Pull off the water pump shaft (see Water Pump Shaft Re- moval in the Cooling System chapter).
  • Page 162 6-14 ENGINE RIGHT SIDE Right Engine Cover • Apply a non-permanent locking agent to the threads of the advancer lever mounting Allen bolts. • Tighten the advancer lever mounting Allen bolts [A]. Torque - Exhaust Valve Advancer Lever Mounting Allen Bolts: 3.9 N·m (0.4 kgf·m, 35 in·lb) •...
  • Page 163: Clutch

    [B]. • Remove the push rod holder assembly [A], friction plates, steel plates, and push rod [B]. • For KX125, Remove steel boll [C]. • Remove the clutch hub nut [A] and washer. NOTE ○ Use the clutch holder [B] to prevent the clutch hub from rotating.
  • Page 164: Clutch Installation

    • For KX125, the grooves [A] on the friction plate surfaces are cut tangentially and radially, install the first and last friction plates [B] so that the grooves run toward the cen- ter in the direction of the clutch housing rotation (counter- clockwise viewed from the engine right side).
  • Page 165: Friction And Steel Plates Wear, Damage Inspection

    ENGINE RIGHT SIDE 6-17 Clutch • For KX125; check the release shaft lever positions [A]. ○ Remove the magneto cover. ○ Pushing the release shaft lever [C] lightly upward mea- sure the distance between the release shaft lever and clutch cable set position of crankcase [D].
  • Page 166: Spring Free Length Measurement

    Remove the clutch (see Clutch Removal). • Remove the clutch cable upper end (see Clutch Cable Removal). ○ For KX125; remove the magneto cover. • Remove the tips [A] of the clutch cable. • Pull the lever and shaft assembly [B] out of the crankcase.
  • Page 167: Release Shaft Installation

    • Apply engine oil to the bearing in the hole of the crankcase. • Insert the release shaft straight in to the hole of the crankcase. • Install the clutch (see Clutch Installation). ○ For KX125; install the magneto cover.
  • Page 168: Shift Pedal Bolt

    6-20 ENGINE RIGHT SIDE External Shift Mechanism External Shift Mechanism Removal • Remove: Shift Pedal Right Engine Cover (see Right Engine Cover Removal) Clutch (see Clutch Removal) • Pull out the external shift shaft [A]. • Remove the bolts [B] and take off the shift ratchet assem- bly [C] with collar.
  • Page 169: External Shift Mechanism Return Spring Pin (kx250)

    ENGINE RIGHT SIDE 6-21 External Shift Mechanism • Instal the shift pedal [A] as shown. 0 ∼ 20 mm (0 ∼ 0.79 in.) [B] • Tighten: Torque - Shift Pedal Bolt: 9.8 N·m (1.0 kgf·m, 87 in·lb) External Shift Mechanism Inspection •...
  • Page 170: Primary Gear

    Remove the right engine cover (see Right Engine Cover Removal) • Remove the clutch (see Clutch Removal). • For KX125, remove the primary gear nut [A], spring washer, woodruff key, primary gear [B], and O-ring. NOTE ○ Use the flywheel & pulley holder to prevent the crank- shaft from the rotating.
  • Page 171: Kickstarter

    ENGINE RIGHT SIDE 6-23 Kickstarter Kickshaft Removal • Remove: Right Engine Cover Clutch Housing • Pull the end of the kick spring [A] out of the hole in the crankcase. • Remove the kickstarter assembly [B]. • Remove the bolts [A], take off the ratchet guide [B]. Kickstarter Assembly Disassembly/Assembly •...
  • Page 172: Idle Gear Removal

    Remove: Right Engine Cover (see Right Engine Cover Removal) Clutch Housing (see Clutch Removal) • For KX125, pull off the idle gear. • For KX250, remove the circlip [A] and pull off the idle gear [B]. Special Tool - Outside Circlip Pliers: 57001-144 Idle Gear Installation •...
  • Page 173 ENGINE REMOVAL/INSTALLATION 7-1 Engine Removal/Installation Table of Contents Exploded View........................Special Tool ..........................Engine Removal/Installation ....................Engine Removal........................ Engine Installation......................
  • Page 174: Exploded View

    7-2 ENGINE REMOVAL/INSTALLATION Exploded View...
  • Page 175: Torque Kgf·m

    Torque Fastener Remarks N·m kgf·m ft·lb Engine Mounting Nuts: KX125/250-M1 KX125/250-M2 ∼ Engine Mounting Bracket Nut (Engine Side 10 mm): KX125/250-M1 KX125/250-M2 ∼ Engine Mounting Bracket Nuts (Frame Side 8 mm) Swingarm Pivot Shaft Nut 10.0 5. Frame 6. Engine Mounting Bracket 7.
  • Page 176: Special Tool

    7-4 ENGINE REMOVAL/INSTALLATION Special Tool Jack: 57001-1238...
  • Page 177: Engine Removal/installation

    ENGINE REMOVAL/INSTALLATION 7-5 Engine Removal/Installation Engine Removal • Drain the engine oil (see Transmission Oil Change in the Periodic Maintenance chapter). • Drain the coolant (see Coolant Inspection in the Periodic Maintenance chapter). • Remove: Radiator Shrouds Side Covers Seat Fuel Tank Water Hoses Radiators...
  • Page 178: Engine Removal

    Engine Installation • Tighten the following nuts. Torque - Engine Mounting Nuts: 44 N·m (4.5 kgf·m, 33 ft·lb) (KX125/250-M1) 49 N·m (5.0 kgf·m, 36 ft·lb) (KX125/250-M2∼) Engine Mounting Bracket Nuts 10 mm: 44 N·m (4.5 kgf·m, 33 ft·lb) (KX125/250-M1) 49 N·m (5.0 kgf·m, 36 ft·lb) (KX125/250-M2∼) Engine Mounting Bracket Nuts 8 mm: 29 N·m (3.0 kgf·m, 22 ft·lb)
  • Page 179 ENGINE BOTTOM END/TRANSMISSION 8-1 Engine Bottom End/Transmission Table of Contents Exploded View........................Specifications ......................... Special Tools and Sealant ...................... Transmission Oil ........................Oil Level Inspection......................Oil Change ........................Crankcase ..........................Crankcase Splitting ......................Crankcase Disassembly ....................8-10 Crankcase Assembly ......................8-11 Crankshaft, Connecting Rod ....................
  • Page 180: Exploded View

    8-2 ENGINE BOTTOM END/TRANSMISSION Exploded View KX125:...
  • Page 181: Output Shaft Bearing Retaining Screws

    Output Shaft Bearing Retaining Screws 0.55 48 in·lb Shift Drum Bearing Retaining Screws (KX125-M1) 0.65 56 in·lb Shift Drum Bearing Retaining Bolts (KX125-M2 ∼) 78 in·lb Engine Oil Drain Bolt 14.5 Crankcase Bolts 78 in·lb Flywheel Bolt Shift Drum Operating Cam Bolt 7.
  • Page 182 8-4 ENGINE BOTTOM END/TRANSMISSION Exploded View KX250:...
  • Page 183 ENGINE BOTTOM END/TRANSMISSION 8-5 Exploded View Torque Fastener Remarks N·m kgf·m ft·lb Crankcase Bolts 78 in·lb Output Shaft Bearing Retaining Screws 0.55 48 in·lb Shift Drum Bearing Retaining Bolts 78 in·lb Engine Oil Drain Bolt 14.5 Drive Shaft Bearing Retaining Bolts 78 in·lb Flywheel Nut Shift Drum Operating Cam Bolt...
  • Page 184: Specifications

    8-6 ENGINE BOTTOM END/TRANSMISSION Specifications Standard Item Service Limit KX125/250-M1 Transmission Oil Grade API SE, SF or SG – – – API SA or SJ with JASO MA API SH, SJ or SL with JASO MA (KX125M7F ∼) Viscosity SAE 10W-40 –...
  • Page 185: Special Tools And Sealant

    ENGINE BOTTOM END/TRANSMISSION 8-7 Special Tools and Sealant Bearing Puller Adapter: Bearing Driver Set: 57001-136 57001-1129 Outside Circlip Pliers: Crankshaft Jig: 57001-144 57001-1174 Bearing Puller: Kawasaki Bond (Liquid Gasket - Silver): 57001-158 92104-002 Crankcase Splitting Tool Assembly: 57001-1098...
  • Page 186: Transmission Oil

    8-8 ENGINE BOTTOM END/TRANSMISSION Transmission Oil In order for the transmission and clutch to function prop- erly, always maintain the transmission oil at the proper level and change the oil periodically. WARNING Motorcycle operation with insufficient, deteri- orated, or contaminated transmission oil will accelerated wear and may result in transmission seizure, and injury.
  • Page 187: Crankcase

    Gear Set Lever [A] Shift Drum Operating Cam [B] Output Shaft Sleeve [C] and O-ring [D] (KX250, O-rings) Flywheel Magneto and Stator (see Flywheel Magneto Removal in the Electrical System chapter) Reed Valve (KX125) (see Reed Valve Removal in the Fuel System chapter)
  • Page 188: Crankcase Disassembly

    8-10 ENGINE BOTTOM END/TRANSMISSION Crankcase • Remove the crankcase bolts [A]. • Install the crankcase splitting tool [A] and bearing puller adapter [B] into the left side of the crankcase. Be certain to screw the tool in all the way. Special Tools - Crankcase Splitting Tool Assembly: 57001 -1098 Bearing Puller Adapter: 57001-136...
  • Page 189: Crankcase Assembly

    [A] Oil Seal [B] Needle Bearing [C] Needle Bearing Position KX125-M1 ∼ M2: 3.5 ±0.2 mm (0.138 ±0.008 in.) KX125-M3 ∼: 3.3 ±0.2 mm (0.130 ±0.008 in.) ○ If the crankshaft bearings stay on the crankshaft when splitting the crankcase, remove the bearings from the...
  • Page 190 Crankcase • Check to see that the crankcase knock pins [A] and O-ring [B] (KX125) are in place on the right crankcase half. If any of them has been removed, replace it with a new one. • Apply liquid gasket to the mating surface [A] of the crankcase half.
  • Page 191 ENGINE BOTTOM END/TRANSMISSION 8-13 Crankcase • Check to see that the crankshaft, drive shaft, and output shaft all turn freely (in the neutral position). If the crankshaft will not turn, probably the crankshaft is not centered; tap the appropriate end of the crankshaft with a mallet to reposition it.
  • Page 192: Crankshaft, Connecting Rod

    8-14 ENGINE BOTTOM END/TRANSMISSION Crankshaft, Connecting Rod Crankshaft Removal • Split the crankcase (see Crankcase Splitting). • Remove the transmission shafts (see Transmission Shaft Removal). • Using a press, remove the crankshaft from the right crankcase. ○ If the bearings stay on the crankshaft when splitting the crankcase or removing the crankshaft from the right crankcase, remove the bearings from the crankshaft with a bearing puller [A] and adapter [B].
  • Page 193: Connecting Rod Big End Radial Clearance Inspection

    • Turn the crankshaft slowly. The maximum difference in gauge readings is the crankshaft runout. (A): KX125 - 8.0 mm (0.315 in.) KX250 - 8.5 mm (0.335 in.) Crankshaft Runout Standard: TIR 0.03 mm (0.0012 in.) or less Service Limit: TIR 0.05 mm (0.002 in.)
  • Page 194: Crankshaft Alignment Inspection

    8-16 ENGINE BOTTOM END/TRANSMISSION Crankshaft, Connecting Rod Crankshaft Alignment Inspection • In the case of horizontal misalignment, which is the most common, strike the projecting rim of the flywheel with a plastic, soft lead, or brass hammer as indicated in the figure.
  • Page 195: Transmission

    The drive shaft gears can be identified by size; the smallest diameter gear is 1st gear, and the largest is 5th (KX250) or 6th (KX125). Be sure that all parts are put back in the correct sequence, and facing the proper di- rection, and that all circlips and the washers are properly in place.
  • Page 196 The output shaft gears can be identified by size; the largest diameter gear is 1st gear, and the smallest is 5th (KX250) or 6th (KX125). Be sure that all parts are put back in the correct sequence and facing the proper direction, and that all circlips are properly in place.
  • Page 197: Shift Drum And Fork Installation

    • Tighten the shift drum bearing retaining screws or bolts. Torque - Shift Drum Bearing Retaining Screws: 6.4 N·m (0.65 kgf·m, 56 in·lb) (KX125 ∼ M1) Shift Drum Bearing Retaining bolts: 8.8 N·m (0.9 kgf·m, 78 in·lb) (KX250), (KX125-M2 ∼) •...
  • Page 198: Shift Fork Bending Inspection

    If the thickness of a shift fork ear is less than the service limit, the shift fork must be replaced. Gear Shift Fork Ear Thickness Standard: 4.9 ∼ 5.0 mm (0.1768 ∼ 0.1969 in.) KX125 4.4 ∼ 4.5 mm (0.1732 ∼ 0.1772 in.) KX250 Service Limit: KX125 4.8 mm (0.189 in.)
  • Page 199: Gear Damage Inspection

    ENGINE BOTTOM END/TRANSMISSION 8-21 Transmission Gear Damage Inspection • Visually inspect the gear teeth on the transmission gears. Repair lightly damaged gear teeth with an oilstone. The gear must be replaced if the teeth are badly damaged. When the gear is repaired or replaced, the driving gear should also be inspected and repaired or replaced if nec- essary.
  • Page 201 WHEELS/TIRES 9-1 Wheels/Tires Table of Contents Exploded View........................Specifications ......................... Special Tools .......................... Wheels (Rims) ........................Front Wheel Removal ....................... Front Wheel Installation ....................Rear Wheel Removal......................Rear Wheel Installation..................... Wheels Inspection......................9-10 Spoke Tightness Inspection ....................9-10 Rim Runout Inspection...................... 9-10 Axle Inspection........................
  • Page 202: Exploded View

    9-2 WHEELS/TIRES Exploded View...
  • Page 203: Front Axle Nut

    11.0 5. Spoke 6. Front Tire 7. Rim 8. Front Axle 9. Swingarm 10. Rear Tire 11. Rear Axle A: KX125/250-M1 model B: KX125/250-M2 model∼ G: Apply grease. WL: Apply soap and water solution, or rubber lubricant. R: Replacement Parts...
  • Page 204: Specifications

    – – – Tires Standard Tire: KX125 Front: Size 80/100-21 51M – – – Make DUNLOP Type: (KX125-M1 ∼ M2) D739FA, Tube (EUR) D755FJ, Tube (KX125-M3 ∼) D742F, Tube (other than EUR) Rear: Size 100/90-19 57M – – – Make DUNLOP Type: (KX125-M1 ∼...
  • Page 205: Special Tools

    WHEELS/TIRES 9-5 Special Tools Inside Circlip Pliers: Bearing Driver Set: 57001-143 57001-1129 Rim Protector: Jack: 57001-1063 57001-1238 Bead Breaker Assembly: 57001-1072...
  • Page 206: Wheels (rims)

    Using the jack [A] under the frame, and stabilize the mo- torcycle, and raise the front wheel off the ground. Special Tool - Jack: 57001-1238 • For KX125/250-M1 model, unscrew the guard screws [A] and remove the guard [B]. • Unscrew the axle nut [A].
  • Page 207: Front Wheel Installation

    WHEELS/TIRES 9-7 Wheels (Rims) • For KX125/250-M2 model∼; as shown in the figure. • Insert a wood wedge between the disc brake pads. This prevents them from being moved out of their proper posi- tion, should the brake lever be squeezed accidentally.
  • Page 208: Rear Wheel Removal

    9-8 WHEELS/TIRES Wheels (Rims) Rear Wheel Removal • Using the jack under the frame so that the rear wheel is raised off the ground. Special Tool - Jack: 57001-1238 • Remove the clip [A] from the master link using pliers, and free the drive chain [B] from the rear sprocket.
  • Page 209 WHEELS/TIRES 9-9 Wheels (Rims) • Fit the projection on the cap to the groove on the collar. • Install the collars [A] on the left and right side of the hub. • Install the drive chain. Install the master link clip [A] so that the closed end [B] of the “U”...
  • Page 210: Wheels Inspection

    9-10 WHEELS/TIRES Wheels (Rims) Wheels Inspection • Place the jack under the frame so that the front/rear wheel is raised off the ground. Special Tool - Jack: 57001-1238 • Spin the wheel lightly, and check for roughness or binding. If roughness or binding is found, replace the hub bearings. •...
  • Page 211: Tires

    WHEELS/TIRES 9-11 Tires Tire Air Pressure Inspection/Adjustment • Refer to the Tire Air Pressure Inspection/Adjustment in the Periodic Maintenance chapter. Tires Inspection • Refer to the Tires Inspection in the Periodic Maintenance chapter. Tire Removal CAUTION Do not lay the wheel on the ground with the disc facing down.
  • Page 212: Tire Installation

    9-12 WHEELS/TIRES Tires Tire Installation NOTE ○ The tires should be installed so that the year and week of manufacture [A] or the ID serial faces to left side. • Inspect the rim and tire, and replace them if necessary. •...
  • Page 213: Hub Bearings

    WHEELS/TIRES 9-13 Hub Bearings Hub Bearing Removal • Remove the wheel (see Wheel Removal). CAUTION Do not lay the wheel on the ground with the disc facing down. This can damage or warp the disc. Place blocks under the wheel so that the disc does not touch the ground.
  • Page 215 FINAL DRIVE 10-1 Final Drive Table of Contents Exploded View........................10-2 Specifications ......................... 10-4 Special Tools .......................... 10-5 Drive Chain..........................10-6 Drive Chain Slack Inspection .................... 10-6 Drive Chain Slack Adjustment ..................10-6 Wheel Alignment Inspection ..................... 10-6 Wheel Alignment Adjustment.................... 10-6 Drive Chain Wear Inspection ....................
  • Page 216: Exploded View

    10-2 FINAL DRIVE Exploded View...
  • Page 217: Rear Sprocket Nuts

    5. Output Shaft 6. Chain Slipper 7. Swingarm 8. Chain Guide 9. Locknut 10. Adjusting Bolt 11. Chain Adjuster 12. Drive Chain 13. Rear Sprocket 14. Rear Axle A: KX125-M1 ∼ M2 Model G: Apply grease. O: Apply oil. R: Replacement Parts...
  • Page 218: Specifications

    DAIDO – – – Type: D.I.D 520DMA2 – – – Length: KX125-M1 112 Links – – – KX125-M2 ∼ 114 Links – – – KX250 114 Links – – – Sprocket TIR 0.5 mm (0.020 Rear Sprocket Warp (Runout) TIR 0.4 mm (0.016 in.) or less...
  • Page 219: Special Tools

    FINAL DRIVE 10-5 Special Tools Outside Circlip Pliers: Jack: 57001-144 57001-1238...
  • Page 220: Drive Chain

    10-6 FINAL DRIVE Drive Chain Drive Chain Slack Inspection • Refer to the Drive Chain Inspection in the Periodic Main- tenance chapter. Drive Chain Slack Adjustment • Refer to the Drive Chain Inspection in the Periodic main- tenance chapter. Wheel Alignment Inspection •...
  • Page 221: Sprockets

    FINAL DRIVE 10-7 Sprockets Engine Sprocket Removal • Remove: Engine Sprocket Cover [A] Drive Chain [B] (free of engine sprocket) • Remove the circlip [C], and pull off the engine sprocket [D]. Special Tool - Outside Circlip Pliers: 57001-144 Engine Sprocket Installation •...
  • Page 223 BRAKES 11-1 Brakes Table of Contents Exploded View........................11-2 Specifications ......................... 11-6 Special Tools .......................... 11-7 Brake Lever, Brake Pedal....................... 11-8 Brake Lever Play Adjustment.................... 11-8 Brake Pedal Position/Pedal Play Adjustment ..............11-8 Brake Pedal Removal ....................... 11-8 Brake Pedal Installation ....................11-9 Brake Fluid ..........................
  • Page 224: Exploded View

    11-2 BRAKES Exploded View...
  • Page 225: Front Master Cylinder Clamp Bolts

    13. Brake Hose 14. Clamps 15. Front Caliper 16. Brake Pad 17. Piston 18. Front Disc A: KX125/250-M1 model B: KX125/250-M2 model ∼ BF: Apply brake fluid. L: Apply a non-permanent locking agent. R: Replacement Parts Si: Apply Silicone grease.
  • Page 226 11-4 BRAKES Exploded View...
  • Page 227: Brake Pad Bolt

    BRAKES 11-5 Exploded View Torque Fastener Remarks N·m kgf·m ft·lb Brake Hose Banjo Bolts Rear Master Cylinder Mounting Bolts 87 in·lb Rear Master Cylinder Push Rod Locknut Caliper Bleed Valve 69 in·lb Brake Pad Bolt Rear Brake Pad Bolt Plug 0.25 22 in·lb Caliper Holder Shaft...
  • Page 228: Front

    11-6 BRAKES Specifications Item Standard Service Limit Brake Adjustment Brake Lever Play Adjustable (to suit rider) – – – Brake Fluid Recommended Disc Brake Fluid: – – – Type: Front DOT3 or DOT4 – – – Rear DOT4 Brake Pads Lining Thickness: Front 3.8 mm (0.150 in.)
  • Page 229: Special Tools

    BRAKES 11-7 Special Tools Inside Circlip Pliers: Jack: 57001-143 57001-1238...
  • Page 230: Brake Lever, Brake Pedal

    [B] indicated in the figure. Push Rod Locknut [C] Standard Length [B]: 79.3 mm (3.12 in.) (KX125/250-M1) 67.3 mm (2.65 in.) (KX125/250-M2 ∼) If the length is not within the specified length, adjust the clevis [A] as follows. ○...
  • Page 231: Brake Pedal Installation

    BRAKES 11-9 Brake Lever, Brake Pedal • Remove the mounting bolt [A] and take off the brake pedal and return spring [B]. Brake Pedal Installation • Inspect the pedal O-ring for signs of damage. If neces- sary, replace them with new one. •...
  • Page 232: Brake Fluid

    11-10 BRAKES Brake Fluid WARNING When working with the disc brake, observe the pre- cautions listed below. 1. Never reuse old brake fluid. 2. Do not use fluid from a container that has been left unsealed or that has been open for a long time. 3.
  • Page 233: Bleeding The Brake Line

    BRAKES 11-11 Brake Fluid Bleeding the Brake Line The brake fluid has a very low compression coefficient so that almost all the movement of the brake lever or pedal is transmitted directly to the caliper for braking action. Air, however, is easily compressed. When air enters the brake lines, brake lever or pedal movement will be partially used in compressing the air.
  • Page 234 11-12 BRAKES Brake Fluid • Remove the clear plastic hose. • Tighten the bleed valves, and install the rubber caps. Torque - Caliper Bleed Valve: 7.8 N·m (0.8 kgf·m, 69 in·lb) • Check the fluid level. • After bleeding is done, check the brake for good braking power, no brake drag, and no fluid leakage.
  • Page 235: Caliper

    ○ Remove the pads. ○ Pump the brake lever to remove the piston. • For KX125/250-M2 model ∼; as shown in the figure. Rear Brake • Unbolt the guard bolts [A] and remove the rear caliper guard [B]. •...
  • Page 236: Caliper Installation

    11-14 BRAKES Caliper Caliper Installation • Tighten the brake pad bolts if it was removed. Torque - Brake Pad Bolts: 18 N·m (1.8 kgf·m, 13 ft·lb) Front Brake: • Install the caliper and tighten the bolts. Torque - Caliper Mounting Bolts: 25 N·m (2.5 kgf·m, 18 ft·lb) Rear Brake: •...
  • Page 237: Caliper Assembly

    BRAKES 11-15 Caliper Caliper Assembly • Clean the caliper parts except for the pads. CAUTION For cleaning the parts, use only disc brake fluid, isopropyl alcohol, or ethyl alcohol. • Tighten the bleed valve with rubber cap. Torque - Caliper Bleed Valve: 7.8 N·m (0.8 kgf·m, 69 in·lb) •...
  • Page 238: Piston Cylinder Damage Inspection

    Remove the plug and the pad bolt [A]. • Take the piston side pad [B]. • Push the caliper holder toward the piston, and then re- move another pad [C] from the caliper holder. • For KX125/250-M2 model∼; as shown in the figure.
  • Page 239: Rear Brake Pad Bolt Plug

    BRAKES 11-17 Caliper Brake Pad Installation • Push the caliper pistons in by hand as far as they will go. • Install the piston side pad first, and then another pad. • Tighten the brake pad bolt and plug. Torque - Brake Pad Bolt: 18 N·m (1.8 kgf·m, 13 ft·lb) Rear Brake Pad Bolt Plug: 2.5 N·m (0.25 kgf·m, 22 in·lb) •...
  • Page 240: Master Cylinder

    11-18 BRAKES Master Cylinder CAUTION Brake fluid quickly ruins painted or plastic sur- faces; any spilled fluid should be completely wished up immediately. Front Master Cylinder Removal • Remove the banjo bolt [A] to disconnect the upper brake hose from the master cylinder (see Brake Hose Re- moval/Installation).
  • Page 241: Rear Master Cylinder Installation

    BRAKES 11-19 Master Cylinder Rear Master Cylinder Installation • Replace the cotter pin with a new one. • Replace the washers are on each side of hose fitting with new ones. • Tighten the following: Torque - Brake Hose Banjo Bolt: 25 N·m (2.5 kgf·m, 18 ft·lb) Rear Master Cylinder Mounting Bolts: 9.8 N·m (1.0 kgf·m, 87 in·lb) •...
  • Page 242: Master Cylinder Assembly

    11-20 BRAKES Master Cylinder Master Cylinder Assembly • Before assembly, clean all parts including the master cylinder with brake fluid or alcohol. • Apply brake fluid to the removed parts and to the inner wall of the cylinder. CAUTION Except for the disc pads and disc, use only disc brake fluid, isopropyl alcohol, or ethyl alcohol for cleaning brake parts.
  • Page 243: Brake Disk

    BRAKES 11-21 Brake Disk Brake Disc Inspection • Visually inspect the disc [A]. If it is scratched or damaged, replace the disc. • Measure the thickness of each disc at the point [B] where it has worn the most. Replace the disc if it has worn past the service limit. Thickness Standard: 2.85 ∼...
  • Page 244: Brake Hose

    11-22 BRAKES Brake Hose Brake Hose Removal/Installation CAUTION Brake fluid quickly ruins painted or plastic sur- faces; any spilled fluid should be completely wiped up immediately with watered cloth. • When removing the brake hose, take care not to spill the brake fluid on the painted or plastic parts.
  • Page 245 SUSPENSION 12-1 Suspension Table of Contents Exploded View........12-2 Rear Shock Absorber Installation 12-34 Specifications ........12-10 Spring Replacement ....12-34 Special Tools ........12-14 Rear Shock Absorber Front Fork .......... 12-16 Disassembly (Oil Change) ..12-35 Air Pressure Inspection....12-16 Rear Shock Absorber Assembly ..
  • Page 246: Exploded View

    12-2 SUSPENSION Exploded View KX125/250-M1:...
  • Page 247: Front Fork Top Plug

    SUSPENSION 12-3 Exploded View Torque Fastener Remarks N·m kgf·m ft·lb Front Fork Top Plug Front Fork Clamp Bolts (Upper, Lower) 14.5 Steering Stem Head Nut 10.0 Piston Rod Nut Front Axle Clamp Bolts 14.5 Front Fork Cylinder Valve Assembly 7. Screw 8.
  • Page 248 12-4 SUSPENSION Exploded View KX125/250-M2∼...
  • Page 249: Front Axle Clamp Bolts

    SUSPENSION 12-5 Exploded View Torque Fastener Remarks N·m kgf·m ft·lb Front Fork Top Plug Front Fork Clamp Bolts (Upper, Lower) 14.5 Steering Stem Head Nut 10.0 Piston Rod Nut Front Axle Clamp Bolts 14.5 Front Fork Cylinder Valve Assembly 7. Screw 8.
  • Page 250 12-6 SUSPENSION Exploded View KX125/250-M1:...
  • Page 251 SUSPENSION 12-7 Exploded View Torque Fastener Remarks N·m kgf·m ft·lb Swingarm Pivot Shaft Nut 10.0 Rocker Arm Pivot Nut Tie-Rod Mounting Nut (Front, Rear) Rear Shock Absorber Mounting Nut (Upper) Rear Shock Absorber Mounting Nut (Lower) 6. Pivot Shaft 7. Swingarm 8.
  • Page 252 12-8 SUSPENSION Exploded View KX125/250-M2∼...
  • Page 253 SUSPENSION 12-9 Exploded View Torque Fastener Remarks N·m kgf·m ft·lb Swingarm Pivot Shaft Nut 10.0 Tie-Rod Mounting Nut (Front, Rear) Rocker Arm Pivot Nut Rear Shock Absorber Mounting Nut (Upper) Rear Shock Absorber Mounting Nut (Lower) 6. Pivot Shaft 7. Swingarm 8.
  • Page 254: Specifications

    12-10 SUSPENSION Specifications KX125/250-M1: Item Standard Service Limit Front Fork Air Pressure Atmospheric pressure – – – Rebound Damping Adjustment (Adjustable Range) (from the seated position adjuster 13 clicks counterclockwise 16 clicks turned fully clockwise): Compression Damping Adjustment (from the seated position adjuster...
  • Page 255 SUSPENSION 12-11 Specifications Item Standard Service Limit Tie-Rod, Rocker Arm: Sleeve Outside Diameter: 19.987 ∼ 20.000 mm (0.7869 ∼ Large 19.85 mm (0.781 in.) 0.7874 in.) 15.987 ∼ 16.000 mm (0.6294 ∼ Small 15.85 mm (0.624 in.) 0.6299 in.) Rocker Arm Mounting Bolt Runout TIR 0.1 mm (0.004 in.) or less TIR 0.2 mm (0.008 in.)
  • Page 256 12-12 SUSPENSION Specifications KX125/250-M2 ∼ : Item Standard Service Limit Front Fork Air Pressure Atmospheric pressure – – – Rebound Damping Adjustment (Adjustable Range) (from the seated position adjuster 14 clicks counterclockwise 16 clicks turned fully clockwise): Compression Damping Adjustment...
  • Page 257 SUSPENSION 12-13 Specifications Item Standard Service Limit Tie-Rod, Rocker Arm Sleeve Outside Diameter: 19.987 ∼ 20.000 mm (0.7869 ∼ Large 19.85 mm (0.781 in.) 0.7874 in.) 15.987 ∼ 16.000 mm (0.6294 ∼ Small 15.85 mm (0.624 in.) 0.6299 in.) Rocker Arm Mounting Bolt Runout TIR 0.1 mm (0.004 in.) or less TIR 0.2 mm (0.008 in.)
  • Page 258: Special Tools

    12-14 SUSPENSION Special Tools Oil Seal & Bearing Remover: Jack: 57001-1058 57001-1238 Steering Stem Nut Wrench: Bearing Remover Shaft, 9: 57001-1100 57001-1265 Hook Wrench R37.5, R42: Bearing Remover Head, 15 × 17: 57001-1101 57001-1267 Bearing Driver Set: Fork Piston Rod Puller, M12 × 1.25: 57001-1129 57001-1289 Fork Outer Tube Weight:...
  • Page 259 SUSPENSION 12-15 Special Tools Fork Cylinder Holder: Fork Cylinder Holder: 57001-1413 57001-1573 Fork Oil Seal Driver, 48: 57001-1509...
  • Page 260: Front Fork

    NOTE ○ The left and right fork legs must have the same shock damping. Seated positions: adjuster turned fully clockwise [A]. Rebound Damping Adjuster Setting Standard: KX125-M1: 13 clicks KX125-M2∼: 14 clicks KX250-M1: 13 clicks KX250-M2∼: 14 clicks...
  • Page 261: Compression Damping Adjustment

    Brake Hose Guard [A] Brake Hose Clamps [B] Fork Protectors [C] Number Plate Handlebar • For KX125/250-M2 model ∼; note the following. ○ Raise the front wheel off the ground using a jack. Special Tool - Jack: 57001-1238 ○ Remove:...
  • Page 262 [A] until their stepped portion contacts the dust seals [B] on the lower end of the outer tubes [C]. • For KX125/250-M2 model ∼; as shown in the figure. • Place a stand or other suitable support [A] under the front wheel.
  • Page 263 100 ∼ 145 mm (3.94 ∼ 5.71 in.) KX125/250-M1: KX125/250-M2 ∼: 70 ∼ 120 mm (2.76 ∼ 4.72 in.) If no oil is drawn out, there is insufficient oil in the fork tube. Pour in enough oil, then pump out the excess oil.
  • Page 264 Check both top plug O-ring [C] for damage and replace them if necessary. • For KX125/250-M2 model ∼; as shown in the figure. • While holding the piston rod nut [A] with a 17 mm (0.67 in.) wrench [B], tighten the top plug [C] against the piston rod.
  • Page 265: Oil Change/oil Level Adjustment (each Fork Leg)

    Remove the caliper [D] from the fork leg to be removed, and rest the caliper on some kind of stand so that it doesn’t dangle. • For KX125/250-M2 model; note the following. ○ Remove the fork protectors [A]. ○ Remove the front brake hose clamps [B].
  • Page 266: Front Fork Disassembly (each Fork Leg)

    ○ For KX125/250-M1 model, pull the fork spring [A] away from the top plug a little and slip the spanner wrench [B] on the top of the spring seat and put it on the piston rod nut [C].
  • Page 267 To discharge the fork oil, pump the piston rod up [C] and down ten times. • Remove the piston rod nut [A] and the spring guide [B]. Cylinder Unit Removal (KX125/250-M1) • Clean the bottom of the inner tube. •...
  • Page 268 12-24 SUSPENSION Front Fork Cylinder Unit Removal (KX125/250-M2 ∼) • Using the spanner wrenchs [A], loosen the guide stay nut [B]. • Remove the snap ring [A]. • Remove the O-ring [B], the guide stay nut [C], the stopper [D] and the piston holder [E].
  • Page 269 SUSPENSION 12-25 Front Fork CAUTION Do not disassemble the air chamber [A] by remov- ing the spring [B] because the sealed air into the cylinder unit may be leaked. • Pull the piston rod assembly [A] out of the bottom of the cylinder unit [B].
  • Page 270: Front Fork Assembly

    Remove the guide bushes [A], washer [B], oil seal [C], retaining ring [D], and dust seal [E] from the inner tube. • For KX125/250-M2 model ∼; remove the guide bushes [A], collar [B], oil seal [C], retaining ring [D], and dust seal [E] from the inner tube.
  • Page 271 SUSPENSION 12-27 Front Fork Install Inner Cylinder (KX125/250-M1) • Install the cylinder unit. • Check the O-ring [A] on the cylinder valve assembly [B], and replace it with a new one. • Replace the gasket [C] with a new one.
  • Page 272 Install the spring guide [A] so that the thinner portion end [B] is down. • Screw on the piston rod nut [C] fully. • For KX125/250-M2 ∼; as shown in the figure. • Insert the rebound damping adjuster rod [A] into the piston rod. •...
  • Page 273: Inner Tube Inspection

    [C] against the top plug. Torque - Piston Rod Nut: 28 N·m (2.9 kgf·m, 21 ft·lb) • For KX125/250-M2 model∼; as shown in the figure. • Pull out the fork spring holder, raise the outer tube and screw the top plug into it.
  • Page 274: Guide Bush Inspection

    12-30 SUSPENSION Front Fork Guide Bush Inspection • Visually inspect the guide bushes [A], and replace them if necessary. Dust Seal/Oil Seal Inspection • Inspect the dust seal [A] for any signs of deterioration or damage. Replace it if necessary. •...
  • Page 275: Rear Suspension (uni-trak)

    If the damper setting feels too soft or too stiff, adjust it in accordance with the following table: • For KX125/250-M2 model∼; as shown in the figure. [A]: Rebound Damping Adjuster Seated position: adjuster turned fully clockwise [A]. Rebound Damping Adjuster Setting...
  • Page 276: Compression Damping

    If the damping feels too soft or too stiff, adjust it in accor- dance with the following table. Seated position: adjuster turned fully clockwise [A]. Compression Damping Standard: KX125: 13 clicks KX250-M1: 12 clicks KX250-M2∼: 10 clicks NOTE ○...
  • Page 277: Spring Tension Inspection

    Special Tool - Steering Stem Nut Wrench: 57001-1100 Spring Preload Adjustment (Adjusting nut position [A] from the center of the mounting hole) Standard: KX125-M1: 112 mm (4.41 in.) KX125-M2∼: 111 mm (4.37 in.) KX250-M1: 117 mm (4.61 in.) KX250-M2∼:...
  • Page 278: Rear Shock Absorber Installation

    • Remove the rear shock absorber lower mounting bolt [B]. • For KX125/250-M2 model∼; note the following. ○ Remove the tie-rod rear mounting bolt [A]. ○ Remove the rear shock absorber lower mounting bolt [B].
  • Page 279: Rear Shock Absorber Disassembly (oil Change)

    SUSPENSION 12-35 Rear Suspension (Uni-Trak) • Using the hook wrenches [C], loosen the locknut [B] and turn the adjusting nut [A] all way up. Special Tool - Hook Wrench R37.5, R42: 57001-1101 • Remove the rear shock absorber from the vise. •...
  • Page 280 12-36 SUSPENSION Rear Suspension (Uni-Trak) • For KX125/250-M2 model∼; note the following. ○ Adjust the gas reservoir damping adjusters [A] to the soft- est position. ○ Remove the air bleeder bolt [B] and pump the rear shock to drain the oil out of the rear shock body.
  • Page 281: Rear Shock Absorber Assembly

    SUSPENSION 12-37 Rear Suspension (Uni-Trak) Rear Shock Absorber Assembly • Pour KYB K2-C (SAE 5W or Bel-Ray SE2 #40) oil into the gas reservoir to 60 ∼ 70 mm (2.63 ∼ 2.76 in.) [A] from the gas reservoir upper end. •...
  • Page 282 12-38 SUSPENSION Rear Suspension (Uni-Trak) • Pull up the gas reservoir cap [A] against the circlip. The end of the gas reservoir cap must align [C] with the end of the gas reservoir [B]. WARNING If the end of the gas reservoir cap and the end of the gas reservoir are not aligned, the circlip is not correctly fitting in the groove in the gas reservoir or is deformed.
  • Page 283 • Fully extend the piston rod assembly. • For KX125/250-M2 model∼; note the following. ○ Hold the lower end of the push rod assembly with a vise. ○ Pump the rear shock up and down several times, and then leave it in the fully extend position for about three minutes.
  • Page 284: Rear Shock Absorber Scrapping

    12-40 SUSPENSION Rear Suspension (Uni-Trak) Rear Shock Absorber Scrapping WARNING Since the reserve tank of the rear shock absorber contains nitrogen gas, do not incinerate the reserve tank without first releasing the gas or it may ex- plode. • Remove the shock absorber (see Rear Shock Absorber Removal).
  • Page 285: Swingarm

    Brake Pedal [B] Tie-rod Rear Mounting Bolt [C] Rear Shock Absorber [D] (see Rear Shock Absorber Re- moval) • For KX125/250-M2 model∼; note the following. ○ Remove: Rear Wheel (see Rear Wheel Removal in the Wheels/Tires chapter) Rear Flap [A]...
  • Page 286: Swingarm Bearing Removal

    Remove the needle bearings using the oil seal & bearing remove [E]. Special Tool - Oil Seal & Bearing Remover: 57001-1058 • For KX125/250-M2 model∼; as shown in the figure. Swingarm Bearing Installation • Replace the needle bearings, grease seals and oil seals with new ones.
  • Page 287: Tie-rod, Rocker Arm

    • Remove the tie-rod rear mounting bolt [B], and then take out the tie-rods [C]. • For KX125/250-M2 model∼; note the following. ○ Remove the tie-rod rear mounting bolt [A]. ○ Remove the tie-rod front mounting bolt [B], and then take out tie-rod [C].
  • Page 288: Rocker Arm Installation

    12-44 SUSPENSION Tie-Rod, Rocker Arm • For KX125/250-M2 model∼; note the following. ○ Remove the tie-rod rear mounting bolt [A]. ○ Remove the rear shock absorber lower mounting bolt [B]. ○ Remove the rocker arm pivot shaft [C] and then remove the rocker arm [D].
  • Page 289: Tie-rod And Rocker Arm Bearing Installation

    Swingarm Pivot Shaft Nut: 98 N·m (10.0 kgf·m, 72 ft·lb) • For KX125/250-M2 model∼; as shown in the figure. Needle Bearing Inspection If there is any doubt as to the condition of either needle bearing, replace the bearing and sleeve as a set.
  • Page 290: Uni-trak Maintenance

    12-46 SUSPENSION Uni-Trak Maintenance Uni-Trak Linkage Inspection • Refer to the Swingarm and Uni-Trak Linkage Inspection in the Periodic Maintenance chapter. Rocker Arm Sleeve Wear Inspection • Pull out the sleeves [A] of the rocker arm, and measure the outside diameter of the sleeve. If the sleeve is worn past the service limit, replace the sleeve.
  • Page 291 13-6 Steering Maintenance......................13-8 Stem Bearing Lubrication....................13-8 Stem Bearing Wear, Damage Inspection................13-8 Steering Stem Warp Inspection ..................13-8 Handlebar ..........................13-9 Handlebar Removal ......................13-9 Handlebar Installation (KX125-M1 ∼ M3/KX250-M1 ∼ M2)..........13-10 Handlebar Installation (KX125M6F ∼)................13-11...
  • Page 292: Exploded View

    13-2 STEERING Exploded View...
  • Page 293 12. Steering Stem 13. Pad AD: Apply adhesive cement G: Apply grease. O: Apply 2 Stroke Oil T: Tighten all snugly, then loosen, retighten to 4.9 N·m (0.5 kgf·m, 43 in·lb). A: KX125-M1 ∼ M3 Model B: KX125M6F Model ∼...
  • Page 294: Special Tools

    13-4 STEERING Special Tools Steering Stem Bearing Driver: Head Pipe Outer Race Driver, 54.5: 57001-137 57001-1077 Steering Stem Bearing Driver Adapter, 34.5: Steering Stem Nut Wrench: 57001-1074 57001-1100 Head Pipe Outer Race Press Shaft: Head Pipe Outer Race Remover ID > 37 mm: 57001-1075 57001-1107 Head Pipe Outer Race Driver, 51.5:...
  • Page 295: Steering Play Inspection

    STEERING 13-5 Steering Steering Play Inspection • Refer to the Steering Inspection in the Periodic Mainte- nance chapter. Steering Play Adjustment • Refer to the Steering Inspection in the Periodic Mainte- nance chapter. Steering Stem, Stem Bearing Removal • Remove: Front Wheel (see Front Wheel Removal in the Wheels/Tires chapter) Brake Hose Clamp...
  • Page 296: Steering Stem, Stem Bearing Installation

    13-6 STEERING Steering • Remove the lower stem bearing inner rase (tapered roller bearing) [A] with its grease seal from the stem using suit- able tools. Steering Stem, Stem Bearing Installation • Replace the bearing outer race with new ones. ○...
  • Page 297 STEERING 13-7 Steering • Settle the bearing in place as follows; ○ Tighten the stem locknut to 39 N·m (4.0 kgf·m, 29 ft·lb) of torque. (To tighten the steering stem locknut to the specified torque, hook the wrench [A] on the stem locknut, and pull the wrench at the hole by 22.2 kg force [B] in the direction shown.) Special Tool - Steering Stem Nut Wrench: 57001-1100...
  • Page 298: Steering Maintenance

    13-8 STEERING Steering Maintenance Stem Bearing Lubrication • Refer to the Steering Stem Bearing Lubrication in the Pe- riodic Maintenance chapter. Stem Bearing Wear, Damage Inspection • Using a high-flash point solvent, wash the upper and lower tapered rollers in the cages, and wipe the upper and lower outer races, which are press-fitted into the frame head pipe, clean off grease and dirt.
  • Page 299: Handlebar

    Left Handlebar Grip [D] • Remove: Throttle Grip Assy [A] Master Cylinder [B] (see Front Master Cylinder Removal in the Brakes chapter) KX125-M1 ∼ M3/KX250-M1 ∼ M2; • Remove: Handlebar Holder Bolts [A] Handlebar Holder (Upper) [B] Handlebar [C] Number Plate [D] KX125M6F ∼;...
  • Page 300: Handlebar Installation (kx125-m1 ~ M3/kx250-m1 ~ M2)

    13-10 STEERING Handlebar ∼ Handlebar Installation (KX125-M1 M3/KX250-M1 ∼ • Apply adhesive cement to the inside of the left handlebar grip. • Install the left handlebar grip so that the triangle mark [A] on the grip point to the punch mark [B] on the handlebar.
  • Page 301: Handlebar Installation (kx125m6f )

    STEERING 13-11 Handlebar ∼ Handlebar Installation (KX125M6F • Apply adhesive cement to the inside of the left handlebar grip. • Install the left handlebar grip and clutch holder as shown. 180 mm (7.09 in.) [A] Frame Horizontal Line [B] 15° ∼ 25° [C] 20°...
  • Page 303 ELECTRICAL SYSTEM 14-1 Electrical System Table of Contents Wiring Diagram........................14-2 Exploded View........................14-4 Specifications ......................... 14-6 Special Tools .......................... 14-7 Precautions..........................14-8 Electrical Wiring........................14-9 Wiring Inspection ......................14-9 Ignition Timing ........................14-10 Ignition Timing Adjustment....................14-10 Flywheel Magneto ........................14-12 Flywheel Magneto Removal....................
  • Page 304: Wiring Diagram

    14-2 ELECTRICAL SYSTEM Wiring Diagram KX125M:...
  • Page 305 ELECTRICAL SYSTEM 14-3 Wiring Diagram KX250M:...
  • Page 306: Exploded View

    14-4 ELECTRICAL SYSTEM Exploded View KX125/250:...
  • Page 307 Flywheel Nut (KX250) Stator Plate Mounting Screw 0.45 39 in·lb Spark Plug Magneto Cover Bolts (KX125/250-M1) 43 in·lb Magneto Cover Bolts (KX125/250-M2 ∼) 35 in·lb C.D.I Unit Mounting Bolts 78 in·lb Ignition Coil Mounting Bolts 78 in·lb 8. Magneto Cover 9.
  • Page 308: Specifications

    14-6 ELECTRICAL SYSTEM Specifications Item Standard Magneto Crankshaft Sensor Air Gap: KX125-M1 ∼ M6F 0.45 ∼ 0.85 mm (0.018 ∼ 0.033 in.) KX125M7F ∼ 0.65 ∼ 1.05 mm (0.026 ∼ 0.041 in.) 0.45 ∼ 0.85 mm (0.018 ∼ 0.033 in.) KX250 180 ∼...
  • Page 309: Special Tools

    ELECTRICAL SYSTEM 14-7 Special Tools Spark Plug Wrench, Hex 21: Peak Voltage Adapter: 57001-110 57001-1415 Flywheel Puller, M12 × 1.75: Flywheel & Pulley Holder: 57001-252 57001-1605 Hand Tester: 57001-1394...
  • Page 310: Precautions

    14-8 ELECTRICAL SYSTEM Precautions There are numbers of important precautions that are musts when servicing electrical systems. Learn and ob- serve all the rules below. ○ The electrical parts should never be struck sharply, as with a hammer, or allowed to fall on a hard surface. Such a shock to the parts can damage them.
  • Page 311: Electrical Wiring

    ELECTRICAL SYSTEM 14-9 Electrical Wiring Wiring Inspection • Visually inspect the wiring for signs of burning, fraying, etc. If any wiring is poor, replace the damaged wiring. • Pull each connector [A] apart and inspect it for corrosion, dirt, and damage. If the connector is corroded or dirty, clean it carefully.
  • Page 312: Ignition Timing

    • Tighten: Torque - Magneto Cover Bolts: 4.9 N·m (0.5 kgf·m, 43 in·lb) (KX125/250-M1) 3.9 N·m (0.4 kgf·m, 35 in·lb) (KX125/250-M2 ∼) The ignition timing can be adjusted for different power band to suit to rider’s preference ability. • Remove the magneto cover.
  • Page 313 39 in·lb) • Install the magneto cover. • Tighten: Torque - Magneto Cover Bolts: 4.9 N·m (0.5 kgf·m, 43 in·lb) (KX125/250-M1) 3.9 N·m (0.4 kgf·m, 35 in·lb) (KX125/250-M2 ∼) • Test ride the motorcycle and readjust the ignition timing if necessary.
  • Page 314: Flywheel Magneto

    Flywheel Magneto Removal • Remove the magneto cover. • Hold the flywheel steady with the flywheel holder [A], and remove the flywheel bolt (KX125) or nut (KX250) [B]. Special Tool - Flywheel & Pulley Holder: 57001-1605 • Remove the flywheel holder. •...
  • Page 315: Flywheel Magneto Installation

    Holding the flywheel steady, with the flywheel holder, and tighten the flywheel bolt (KX125) or nut (KX250). Special Tool - Flywheel & Pulley Holder: 57001-1605 Torque - Flywheel Bolt (KX125): 22 N·m (2.2 kgf·m, 16 ft·lb) Flywheel Nut (KX250): 78 N·m (8.0 kgf·m, 58 ft·lb)
  • Page 316: Flywheel Magneto Inspection

    [B] core.) Crankshaft Sensor Air Gap Standard: KX125-M1 ∼ M6F 0.45 ∼ 0.85 mm (0.018 ∼ 0.033 in.) KX125M7F ∼ 0.65 ∼ 1.05 mm (0.026 ∼ 0.041 in.) 0.45 ∼ 0.85 mm (0.018 ∼ 0.033 in.) KX250 If the gap is incorrect, adjust it (see this chapter).
  • Page 317 ELECTRICAL SYSTEM 14-15 Flywheel Magneto ○ Connect the auxiliary leads between the C.D.I unit [A] (KX125) or main harness connector [A] (KX250) and the magneto lead connector [B]. ○ Connect the hand tester as shown in the table 1. ○...
  • Page 318: Regulator/rectifier Removal (kx250)

    14-16 ELECTRICAL SYSTEM Flywheel Magneto If there is more resistance than shown in the table, or no hand tester reading (infinity) the stator has an open lead and must be replaced. Much less than this resistance means the stator is shorted, and must be replaced. •...
  • Page 319: Regulator/rectifier Inspection (kx250)

    ELECTRICAL SYSTEM 14-17 Flywheel Magneto Regulator/Rectifier Output Voltage Connections Tester Range Reading Tester (+) Tester (–) to 14.2 ∼ 15.2 V 25 V DC Red/White Black/Yellow • Push off the stop switch to stop the engine, and discon- nect the hand tester. If the regulator/rectifier output voltage is kept between the values given in the table, the charging system is consid- ered to be working normally.
  • Page 320: Ignition System

    14-18 ELECTRICAL SYSTEM Ignition System Safety Instructions WARNING The ignition system produces extremely high volt- age. Do not touch the spark plug, ignition coil, or high tension lead while the engine is running, or you could receive a severe electrical shock. Ignition Coil Removal •...
  • Page 321: Spark Plug Cleaning And Inspection

    Refer to the Spark Plug Gap Inspection in the Periodic Maintenance chapter. C.D.I Unit Removal • Remove the number plate. • Disconnect the magneto lead connector [A] (KX125) or main harness connector (KX250). • Unscrew the mounting bolt [B] and remove the C.D.I Unit [C].
  • Page 322: C.d.i Unit Inspection

    • Crank the engine by kicking the pedal several times to measure the peak voltage of the primary ignition coil. Primary Voltage: KX125-M1 ∼ M3: 200 V or above KX125M6F ∼ 160 V or above KX250 150 V or above...
  • Page 323 ELECTRICAL SYSTEM 14-21 Ignition System...
  • Page 324 • To check the peak voltage, do the following procedures. ○ Disconnect the connector of the magneto lead connec- tor from the C.D.I. unit (KX125), or the main harness (KX250). NOTE ○ Measure the voltage with each lead connected cor- rectly.
  • Page 325 ELECTRICAL SYSTEM 14-23 Ignition System Exciter Coil Peak Voltage Check • Disconnect the connector of the magneto lead connec- tor from the C.D.I. unit (KX125), or the main harness (KX250). • To check the peak voltage, do the following procedures. NOTE ○...
  • Page 326: Throttle Sensor Output/input Voltage Check: (kx250)

    14-24 ELECTRICAL SYSTEM Ignition System Throttle Sensor Output/Input Voltage Check: (KX250) NOTE ○ If the variable rheostat is available, refer to throttle sen- sor inspection. • Remove the carburetor lead connector. • Connect the auxiliary leads [A] between carburetor lead connector [B] and main harness connector [C].
  • Page 327: Crankshaft Sensor Inspection

    Loosen the crankshaft sensor screws [A]. • Insert the thickness gauge [B] between the crankshaft sensor core and the timing plat. Thickness Gauge [B] Standard: KX125-M1 ∼ KX125M6F 0.65 mm (0.026 in.) KX125M7F ∼ 0.85 mm (0.033 in.) KX250-M1 ∼ M2 0.65 mm (0.026 in.) •...
  • Page 328: Throttle Sensor

    14-26 ELECTRICAL SYSTEM Throttle Sensor Throttle Sensor Inspection (KX250) NOTE ○ If the variable rheostat is not available, refer to throttle sensor output/input voltage check in the C.D.I Unit in- spection. ○ When inspecting the throttle sensor the throttle valve of the carburetor shall be completely closed and remain the throttle cable connected.
  • Page 329: Fuel Cut Valve

    ELECTRICAL SYSTEM 14-27 Fuel Cut Valve Fuel Cut Valve Removal (KX250) WARNING Gasoline is extremely flammable and can be ex- plosive under certain conditions. Turn the ignition switch OFF. Do not smoke. Make sure the area is well-ventilated and free from any source of flame or sparks;...
  • Page 331 APPENDIX 15-1 Appendix Table of Contents Troubleshooting Guide ......................15-2 Cable, Wire and Hose Routing ....................15-6...
  • Page 332: Troubleshooting Guide

    15-2 APPENDIX Troubleshooting Guide NOTE Piston ring/groove clearance excessive ○ This is not an exhaustive list, giving every Cylinder head gasket damaged possible cause for each problem listed. It Cylinder head warped is meant simply as a rough guide to assist Cylinder base gasket damaged the troubleshooting for some of the more Read valve damaged...
  • Page 333 APPENDIX 15-3 Troubleshooting Guide Poor Running or No Power at High Transmission oil viscosity too high Speed: Crankshaft bearing worn or damaged Firing incorrect: KIPS ports stuck closed: Spark plug dirty, damaged, or maladjusted KIPS ports stuck closed Spark plug cap or high tension wiring dam- KIPS exhaust valves stuck closed (valve aged seizure, or carbon accumulation)
  • Page 334: Abnormal Drive Train Noise

    15-4 APPENDIX Troubleshooting Guide Clutch not disengaging properly: Exhaust pipe leaking at cylinder head con- Clutch lever play excessive nection Clutch plate warped or too rough Crankshaft runout excessive Clutch spring tension uneven Engine mounts loose Transmission oil deteriorated Crankshaft bearing worn Transmission viscosity too high Primary gear worn or chipped Transmission oil level too high...
  • Page 335 APPENDIX 15-5 Troubleshooting Guide Handling and/or Stability Right/left front fork oil level uneven Unsatisfactory: Shock absorption unsatisfactory: Handlebar hard to turn: (Too hard) Control Cable routing incorrect Front fork oil excessive Wiring routing incorrect Front fork oil viscosity too high Steering stem locknut too tight Front fork leg bent Bearing ball damaged...
  • Page 336 15-6 APPENDIX Cable, Wire and Hose Routing KX125:...
  • Page 337 26. Clamps (Install the magneto lead from this side) 27. To the Ignition coil 28. To the Magneto 29. Mating section on the clamp at outside. (KX125-M2 ∼) 30. Run the clutch cable above the number plate mounting bracket. (KX125M6F ∼) A: KX125-M3 ∼ Model B: KX125-M1 ∼...
  • Page 338 15-8 APPENDIX Cable, Wire and Hose Routing KX250:...
  • Page 339 APPENDIX 15-9 Cable, Wire and Hose Routing 1. Throttle Cable 2. Clutch Cable 3. Engine Stop Switch Lead 4. Band 5. Radiator Overflow Tube 6. Right Screen 7. Run the overflow tube backward of the down tube 8. Run the overflow tube outside of the engine mount bracket 9.
  • Page 340 15-10 APPENDIX Cable, Wire and Hose Routing KX125:...
  • Page 341 17. Pay attention to inflection of the radiator overflow tube. 18. Do not face the pinch head of the clamp to the air cleaner duct side. 19. Air Cleaner Duct Side A: KX125-M1 ∼ M3 Model B: KX125M6F ∼ Model...
  • Page 342 15-12 APPENDIX Cable, Wire and Hose Routing KX125M6F ∼: 1. Run the high tension lead inside of the radiator bracket. 2. Tighten together with ignition coil ground lead and magneto ground lead (harness) as figure. 3. Ignition Coil 4. Ignition Coil Ground Lead 5.
  • Page 343 APPENDIX 15-13 Cable, Wire and Hose Routing KX250: 1. Clamps 11. Clamp the air vent hoses with clamps 2. Left Radiator which are installed together with engine 3. Right Radiator sprocket cover and run them along with 4. To the steering stem hole. the engine sprocket cover.
  • Page 344 15-14 APPENDIX Cable, Wire and Hose Routing KX125/250-M1 Model...
  • Page 345 APPENDIX 15-15 Cable, Wire and Hose Routing 1. Front Brake Reservoir 2. Banjo Bolts 3. Clamp 4. Clamp Brackets 5. Hose Guard 6. Front Brake Disc 7. Front Fork Guard 8. Bleed Valves 9. Front Brake Caliper 10. Rear Brake Caliper 11.
  • Page 346 15-16 APPENDIX Cable, Wire and Hose Routing KX125/250-M2 Model∼...
  • Page 347 APPENDIX 15-17 Cable, Wire and Hose Routing 1. Front Brake Reservoir 2. Banjo Bolts 3. Clamp 4. Clamp Brackets 5. Front Brake Disc 6. Front Fork Guard 7. Bleed Valves 8. Front Brake Caliper 9. Rear Brake Caliper 10. Caliper Guard 11.
  • Page 348 MODEL APPLICATION Year Model Beginning Frame No. □ JKAKXRMC 3A000001 or 2003 KX125-M1 JKAKX125MMA000001 □ JKAKXMMC 3A000001 or 2003 KX250-M1 JKAKX250MMA000001 □ JKAKXRMC 4A010001 or 2004 KX125-M2 JKAKX125MMA010001 □ JKAKXMMC 4A010001 or 2004 KX250-M2 JKAKX250MMA010001 □ JKAKXRMC 5A016001 or 2005...

This manual is also suitable for:

Kx250Kx125 2003Kx250 2003

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  • R11000RR Dec 11, 2017 04:00:
    Disculpen soy nuevo,como se descargan los manuales en español??​??
  • Roger Aug 06, 2016 07:44:
    This is gonna be a great big help