Page 1 125 - 160cc 4T Workshop Manual Engine...
Page 2: Table Of Contents
WORKSHOP MANUAL GENERAL INDEX OIL PUMP ASSY Assembling the piston ..............37 ................3 Trouble shooting ....................4 Stripping down the cylinder head ..........38 Exploded view of oil pump ...............5 Checking valve springs .................. 40 Checking valves ..................... 40 Disassembly ..................6 Checking and adjusting valve seating ..........42 Removing the oil pump ..................
Page 3 Workshop Manual General index FlyWheel Cover, FlyWheel MaGneTo, installing the primary pulley ............73 WaTer puMp ................100 disassembling the clutch ...............76 exploded view of water pump............101 disassembling the clutch unit ............77 Exploded view of flywheel cover ..........102 removing the secondary pulley ...........78 Removing the flywheel cover............103 Checks .....................80 Removing the flywheel magneto ..............
Page 4: Oil Pump Assy
WORKSHOP MANUAL OIL PUMP ASSY • The oil pump must be serviced after having removed the ﬂywheel cover. • When the values measured are outside the service limits, renew the oil pump. • Ensure that no foreign material enters the engine when the oil pump is removed. •...
Page 5: Trouble Shooting
WORKSHOP MANUAL OIL PUMP ASSY Standard Service limit Oil pump rotor Radial clearance between 0.15 mm 0.20 mm inner and outer rotors Pump body radial clearance 0.15 - 0.23 mm 0.25 mm Front clearance between 0.05 - 0.10 mm 0.12 mm surfaces Tightening torques Pump body screws...
Page 6: Exploded View Of Oil Pump
WORKSHOP MANUAL OIL PUMP ASSY Exploded view of oil pump 1) Pump cover 2) Pump shaft 3) Inner rotor 4) Outer rotor 5) Pump body 6) Locating dowel 7) Screw 07028001 125 - 160 cc...
Page 7: Disassembly
WORKSHOP MANUAL OIL PUMP ASSY Ensure that no foreign material enters the engine when the oil pump is removed and reﬁtted. Disassembly Remove: • ﬂywheel cover. • rotor and freewheel gear. • chain guard (A) and oil pump assembly. 07028101 Remove circlip (C) from shaft.
Page 8 WORKSHOP MANUAL OIL PUMP ASSY Remove chain ring (D) and chain (E). Check chain for damage or excessive wear. 07028103 Remove chain guard (B). 07028104 125 - 160 cc...
Page 9: Removing The Oil Pump
WORKSHOP MANUAL OIL PUMP ASSY Remove pump assy (F) and pump shaft (G). Check pump for possible damage or excessive wear. 07028100 Removing the oil pump Undo screw (V) and remove pump cover (C). DSCN8392 125 - 160 cc...
Page 10: Oil Pump Body Tolerances
WORKSHOP MANUAL OIL PUMP ASSY Remove inner rotor (L) and outer rotor (M) from pump body (N), paying attention to locating dowel (Q). 07028105 Oil pump body tolerances Measure outside diameter of outer rotor (M) and inside diameter of pump body (N) with callipers and inside micrometer;...
Page 11: Clearance Between Oil Pump Inner And Outer Rotors
WORKSHOP MANUAL OIL PUMP ASSY Clearance between oil pump inner and outer rotors Install inner rotor (L) and outer rotor (M) in pump body (N); measure clearance between inner and outer rotors with feeler gauge. Service limit: 0.20 mm 07028107 Clearance between front surfaces Fit inner rotor (L) and outer rotor (M) in pump body (N) and use a feeler gauge to measure axial clearance between rotors and pump body.
Page 12: Assembly
WORKSHOP MANUAL OIL PUMP ASSY Assembly Wash all parts in clean diesel fuel before reﬁtting. Fit inner rotor (L) and outer rotor (M) in pump body (N), paying attention to locating dowel (Q) 07028109 Fit pump cover (C) and tighten screw (V) to prescribed torque. Cs-N * m 2 ±...
Page 13 WORKSHOP MANUAL OIL PUMP ASSY Ensure ﬁxing holes (P) of pump body (N) are aligned with holes in ﬂywheel cover. If holes are not aligned, screws (V ) cannot be tightened. Fit and tighten two screws (V ) of pump body and chain guard (B); tighten screws to prescribed torque.
Page 14 WORKSHOP MANUAL OIL PUMP ASSY Fit chain ring (D) and chain (E). 07028112 Fit circlip (C) in shaft groove. 07028113 125 - 160 cc...
Page 15 WORKSHOP MANUAL OIL PUMP ASSY Couple chain guard (A) to chain guard (B) and tighten screw (V). Fit rotor assembly and freewheel gear. Fit ﬂywheel cover. 07028114 125 - 160 cc...
Page 16: Cylinder Head, Valves, Cylinder, Piston
WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Working precautions • Valves cover, camshaft, camshaft support, rocker arm, cylinder head and cylinder can be removed without dropping engine from frame. • Take care not to damage mating surfaces when removing valves cover, cylinder head and cylinder. •...
Page 17 WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Standard Service limit 125 cc 160 cc Valve guide Valve stem outside diameter IN 4.975-4.990 mm 4.965 mm 4.955-4.970 mm 4.945 mm Valve guide inside diameter 5.000-5.012 mm 5.040 mm 5.000-5.012 mm 5.040 mm Valve stem to guide 0.100-0.037 mm 0.075 mm...
Page 18 WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Standard Service limit 125 cc 160 cc Piston Piston assembly direction “IN” on intake side — Piston outside diameter 52.37-52.39 mm 57.97-57.99 mm 52.32/57.92 mm Piston pin bore diameter 15.002-15.008 mm 15.04 mm Piston pin diameter 14.994-15.000 mm 14.980 mm...
Page 19: Trouble Shooting
WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Trouble shooting Compression loss can be identiﬁed by measuring pressure directly. If engine fails to start or idles unevenly, check for smoke in engine casing voids. Presence of smoke means damaged, broken or worn piston rings. Irregular full speed Low compression Air inﬁltrating through carburettor couplings...
Page 20: Cylinder Head Exploded View
WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Cylinder head exploded view 1) Valve cotter 2) Valve upper spring retainer 3) Inner valve spring 4) Outer valve spring 5) Valve oil seal 6) Valve lower spring retainer 7) Cylinder head 8) Intake valve 9) Exhaust valve 10) Spark plug 07028109...
Page 21: Cylinder Compression Pressure
WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Cylinder compression pressure NOTE Take measurement with warm engine Remove spark plug cap (A) and spark plug. Fit pressure gauge in spark plug bore to measure compression. Turn over engine with starter motor and throttle body fully open. NOTE The pressure gauge and its components must be assembled in such a way as to avoid pressure losses.
Page 22: Valve Clearance Adjustment
WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Valve clearance adjustment NOTE Checking and adjusting valve clearance must be carried out with warm engine. Remove • valves cover. • clutch cover. DSCN8394 Turn camshaft (by rotating the variator unit nut) until the two timing sprocket references (B) are parallel with cylinder head machined surface (C) and camshaft notch (T) is facing upwards.
Page 23 WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Insert feeler gauge (C) between rocker arm (D) and valve (E) and measure clearance. Valve clearance (warm engine) IN: 0.05 mm EX: 0.15-0.20 mm DSCN8398 125 - 160 cc...
Page 24: Removing Camshaft Support
WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Removing camshaft support Remove: • clutch cover. • valves cover. Turn camshaft counterclockwise by means of variator unit until the two timing sprocket references (B) are parallel with cylinder head machined DSCN8399 surface (C) and camshaft notch (T) is facing upwards. Undo chain tensioner central screw (V).
Page 25 WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Undo screws (V Remove timing sprocket (F). DSCN8401 Unscrew capnuts (D DSCN8402 125 - 160 cc...
Page 26 WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Remove camshaft support (G). DSCN8403 Remove three circlips (S) relative to rocker arm spindles and camshaft. DSCN8404 125 - 160 cc...
Page 27: Removing The Camshaft
WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Remove rocker arm spindles (L). NOTE Remove rocker arm spindles using an M5 screw. DSCN8405 Removing the camshaft Remove camshaft assy (M). DSCN8406 125 - 160 cc...
Page 28: Checks
WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Checks Camshaft Turn bearings (C) to check that they rotate freely and smoothly. Renew camshaft (M) in the presence of noise or tendency to jam. Check cam surfaces for damage and scoring. Measure cam height with micrometer. 07028118 Service limit IN: 30.69 mm...
Page 29: Rocker Arms And Rocker Arm Spindles
WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Rocker arms and rocker arm spindles Check sliding surfaces (N) of rocker arms (Q) and contact surface (P) with valve for possible damage or wear. If wear is excessive, renew rocker arms. 07028120 Measure inside diameter of each bore in rocker arm (Q).
Page 30: Removing The Cylinder Head
WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Removing the cylinder head Remove • throttle body (A) complete with manifold (B) • valves cover. • camshaft support (see removal) • temperature sensor assy (C). DSCN8407 125 - 160 cc...
Page 31 WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Undo screws (V Remove cylinder head (D). DSCN8409 Remove head gasket (E) and locating dowels (F). DSCN8410 125 - 160 cc...
Page 32: Removing The Cylinder
WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Removing the cylinder Disconnect coolant inlet hose (T) from cylinder. DSCN8390 DSCN8409 Remove lower chain guide (G). Undo screw (V). Remove cylinder (L) DSCN8410 125 - 160 cc...
Page 33: Removing The Piston
WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Removing the piston Remove piston pin circlip (A). 07028122 Remove piston pin (B) and piston (C). 07028123 125 - 160 cc...
Page 34 WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Expand piston rings (D) and slide them off over piston (C). • Piston rings are fragile. Do not deform excessively. • Make sure piston rings do not scratch or score surface of piston. 07028124 Scrape carbon deposits off piston (C).
Page 35: Cylinder / Piston Checks
WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Cylinder / piston checks Checking the cylinder Check interior of cylinder for signs of damage or wear. Measure cylinder inside diameter at top, mid point, and bottom (6 measurements); along direction of piston pin and the direction orthogonal to it (axes X –...
Page 36 WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Measure outside diameter of piston pin (B) in contact points with piston and with connecting rod small end (total of three measurements). Service limit: 14.8 mm Calculate tolerance between piston pin (B) and bore in piston. Service limit: 0.04 mm Calculate tolerance between piston pin and small end bore.
Page 37 WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Measure axial clearance between piston ring and groove with feeler gauge. Service limit: • Top piston ring: 0.07 mm • 2nd ring: 0.07 mm Position ring horizontally in lower part of cylinder. Measure ring gap with feeler gauge. Service limit: C - Piston: 52.32 / 57.92 mm 07028130...
Page 38: Assembling The Piston
WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Assembling the piston Insert rings on piston with rings oriented so that punch markings are facing upwards. • Top ring (E) and second ring (F) are not interchangeable. • Keep piston ring gaps staggered at intervals of 120°. After assembly ensure rings can turn freely in grooves.
Page 39: Stripping Down The Cylinder Head
WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Stripping down the cylinder head NOTE Removed parts must be set aside separately and reﬁt in their original positions. Remove valve cotters using speciﬁc tool (A). DSCN8412 125 - 160 cc...
Page 40 WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Remove tool, remove upper retainer (B), outer spring (C), inner spring (D), valve oil seal (F) and lower retainer (G). Once removed, valve oil seal (F) must not be reused. DSCN8413 Remove carbon deposits from combustion chamber (L) and valves. Camera di combustione NOTE Immerse components in petrol to remove carbon deposits.
Page 41: Checking Valve Springs
WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Checking valve springs Measure length of outer spring. Service limit: 33.5 mm Measure length of inner spring. Service limit: 30.8 mm 07028134 Checking valves Insert valve in seat and check movement. Measure diameter of stem in area affected by valve travel. Service limit IN: 4.965 mm EX: 4.945 mm...
Page 42 WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Remove carbon deposits with reamer (M) before measuring inside diameter of valve guide. NOTE Insert valve guide reamer (M) from combustion chamber side. Turn reamer clockwise; counterclockwise rotation of reamer can damage valve guide internal surface. 07028135 Measure inside diameter of valve guide (N).
Page 43: Checking And Adjusting Valve Seating
WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Checking and adjusting valve seating Inspection Clean carbon deposits from valve. Check for possible cracks or distortion of valve seat. Change NOTE Valves cannot be repaired. 07028137 In the presence of breakages, damage, or areas that do not seal correctly, renew the valves.
Page 44 WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON When the valve contact area is located in the upper or lower area of the valve head, correct the position by means of a valve grinding tool. A Low contact area B High contact area 07028139 Measure depth of the valve seating area.
Page 45: Lapping
WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Lapping Svasatore per collare valvola Grind with a valve lapper (D). Refer to valve lapper handbook. Lapping must be performed by hand, exerting pressure of 4-5 kg, always turning the tool in the same direction while working. Lubricate lapper and remove lapping dust during the procedure.
Page 46 WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Use a 32° stone to grind the outermost surface lightly. A Abrasions on valve seat 07028143 Use a 60° stone to grind the contact surface lightly. B Original contact area 07028144 125 - 160 cc...
Page 47 WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Use a 45° stone to grind contact area to required depth. 07028145 Check valve seating area again. If contact area is wider, grind ﬁrst with a 32° stone and then bring it to the required size with a 45°...
Page 48 WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON After correcting, apply a uniform coat of lapping compound and lap the valve. NOTE Rotate the valve slowly during the procedure. Do not work for too long in the same position to avoid wear due to axial misalignment.
Page 49 WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Position lower retainer (G) and new valve oil seal (F) in the valve guide. Lubricate valve stem and interior of valve guide. Slowly insert valve (E) into valve guide. Take care not to damage valve oil seal (F). DSCN8413 The internal and external springs (D-C), have variable coils distance shape must be assembly with close coils shape (A) to the combustion chamber.
Page 50 WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Compress springs with speciﬁc tool (A) and ﬁt cotters. To avoid weakening springs do not compress more than necessary. DSCN8412 125 - 160 cc...
Page 51: Installing The Cylinder
WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Installing the cylinder Check lower chain guide (A) for signs of abrasion, damage or wear caused by misalignment. 07028148 Clean deposits and foreign material from mating surfaces. Check that coolant passages, oilways and screw holes are clean. Fit cylinder gasket (B) and insert locating dowels (C).
Page 52 WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Insert washer under screw (V) and snug screw without tightening. DSCN8410 Fit lower chain guide (A). Turn timing sprocket (lower sprocket) until piston is at TDC (piston surface ﬂush with cylinder rim). Do not turn timing sprocket during following operations. 07028149 125 - 160 cc...
Page 53: Installing The Cylinder Head
WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Position head gasket (C) and insert locating dowels (D). 07028150 Installing the cylinder head Fit head (E) over stud screws and locate it against cylinder. Insert washers under screws (V ) and snug screws without tightening. Insert locating dowels.
Page 54: Installing The Camshaft Support
WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Installing the camshaft support Fit camshaft (A) in support (B). DSCN8406 Lubricate rocker arm spindles (C) sparingly and insert in support (B) and in rocker arms (D). NOTE Insert rocker arm spindles using an M5 screw. DSCN8405 125 - 160 cc...
Page 55 WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Fit circlips (S) in rocker arm spindle bores and in camshaft bore groove. Lubricate cam surfaces. Install assy on cylinder head. DSCN8404 Fit washers and four cap nuts (D Tighten nuts to prescribed torque in two / three passes. Cs-N * m 30 ±...
Page 56 WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Install sprocket (E) on camshaft, maintaining reference marks (F) parallel to head surface (G). Fit timing chain (L) on timing sprocket (E). Fit and tighten sprocket screws (V Cs-N * m 9 ± 15% DSCN8401 Press ratchet (M) on tensioner and push tensioner pin (N) into chain tensioner (P).
Page 57 WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Install chain tensioner and tighten screws (V ) to prescribed torque. Cs-N * m 10 ± 15% Fit tensioner screw (V) and tighten to prescribed torque. Cs-N * m 8 ± 15% • Install throttle body and manifold. •...
Page 58: Checking Engine Timing
WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Checking engine timing Use a slotted screwdriver to remove timing check cap (Q) located on ﬂywheel cover (R). Turn crankshaft by means of variator pulley until aligning reference mark (S) on rotor with reference mark on ﬂywheel cover (V); piston must be at DSCN8390 TDC.
Page 59: Fitting The Valves Cover
WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Fitting the valves cover Fit gasket (A) and insert locating dowels (B) on valves cover (C). DSCN8422 Fit spring (D) in oil union (E) then insert oil union into camshaft. DSCN8396 125 - 160 cc...
Page 60 WORKSHOP MANUAL CYLINDER HEAD, VALVES, CYLINDER, PISTON Fit valves cover (C). Tighten screws (V ), paying attention to the respective sealing washers (F). 125 - 160 cc...
Page 61: Speed Variator-Clutch Unit
WORKSHOP MANUAL SPEED VARIATOR-CLUTCH UNIT Standard Service limit Front pulley Mobile pulley inside diameter 24.007-24.028 mm 24.070 mm Pulley sliding bush outside diameter 23.959-23.980 mm 23.920 mm Roller weights outside diameter 19.95-20.05 mm 19.45 mm Belt thickness 21.7-23.3 mm 20.7 mm Secondary Clutch linings thickness —...
Page 62: Trouble Shooting
WORKSHOP MANUAL SPEED VARIATOR-CLUTCH UNIT Trouble shooting With engine running scooter does Drive belt Worn not move Ramp guide, Worn / Damaged Ramp plate Clutch linings Worn / damaged Variator contrast spring Damaged Engine dies or clutch grabs when Clutch shoes contrast springs Damaged scooter pulls away Low speed...
Page 63: Variator Unit Exploded View
WORKSHOP MANUAL SPEED VARIATOR-CLUTCH UNIT Variator unit exploded view 1) Ramp plate 2) Ramp guide, 3) Roller weight 4) Primary pulley bush 5) O-Ring gasket 6) Mobile primary pulley 7) Sliding bush 8) Fixed primary pulley 9) Washer (14x28x2) 10) Nut (M14x1.5) 07028151 125 - 160 cc...
Page 64: Clutch Unit Exploded View
WORKSHOP MANUAL SPEED VARIATOR-CLUTCH UNIT Clutch unit exploded view 1) Clutch nut 2) Clutch unit 3) Clutch side spring retainer 4) Variator contrast spring 5) Stop washer 6) Spacer 7) Secondary pulley 07028153 125 - 160 cc...
Page 65: Clutch Pulley Exploded View
WORKSHOP MANUAL SPEED VARIATOR-CLUTCH UNIT Clutch pulley exploded view 1) Pulley side spring retainer 2) O-Ring gasket 3) Oil seal 4) Mobile secondary pulley 5) Pin 6) Roller 7) Fixed secondary pulley 8) Bearing 9) Circlip 10) Needle roller bearing 07028152 125 - 160 cc...
Page 66: Clutch Shoes Assy Exploded View
125 - 160 cc...
Page 67: Removing The Clutch Cover
125 - 160 cc...
Page 68: Assembly
WORKSHOP MANUAL SPEED VARIATOR-CLUTCH UNIT Remove gasket (F) of clutch cover (C). Remove locating dowels (E). Assembly To reassemble, perform the above steps in reverse sequence. Primary pulley Disassembly Remove clutch cover. Undo nut (D) and remove its washer. Remove ﬁxed primary pulley (G). DSCN8425 125 - 160 cc...
Page 69 WORKSHOP MANUAL SPEED VARIATOR-CLUTCH UNIT Remove drive belt (A). 07028155 Immobilise internal part of mobile primary pulley (B); now remove pulley together with sliding bush (C). 07028156 125 - 160 cc...
Page 70 WORKSHOP MANUAL SPEED VARIATOR-CLUTCH UNIT Remove pulley sliding bush (C) from mobile primary pulley (B). 07028157 Remove roller ramp plate (E). 07028158 125 - 160 cc...
Page 71: Checks
WORKSHOP MANUAL SPEED VARIATOR-CLUTCH UNIT Remove roller weights (F). 07028159 Checks Drive belt Check drive belt (A) for fraying, wear, or chafﬁng Measure belt thickness. Service limit: 20.7 mm 07028160 125 - 160 cc...
Page 72: Roller Weights
WORKSHOP MANUAL SPEED VARIATOR-CLUTCH UNIT Roller weights Check roller weights (F) for possible wear or damage. Measure roller weights outside diameter. Service limit: 19.45 mm 07028161 Mobile primary pulley Measure inside diameter of mobile pulley (B). Service limit: 24.07 mm 07028162 125 - 160 cc...
Page 73 WORKSHOP MANUAL SPEED VARIATOR-CLUTCH UNIT Check that pulley sliding bush (C) is not worn or damaged. Measure outside diameter of bush (C). Service limit: 23.92 mm 07028163 125 - 160 cc...
Page 74: Installing The Primary Pulley
WORKSHOP MANUAL SPEED VARIATOR-CLUTCH UNIT Installing the primary pulley Insert roller weights (F) in races (H) of mobile primary pulley (B). Seat rollers with end protruding slightly as shown in the photo. 07028164 Fit roller ramp plate (E). 07028165 125 - 160 cc...
Page 75 WORKSHOP MANUAL SPEED VARIATOR-CLUTCH UNIT Insert sliding bush (C) in mobile primary pulley bore (B). 07028166 Manually clamp mobile primary pulley (B) and assemble together with sliding bush (C). 07028167 125 - 160 cc...
Page 76 WORKSHOP MANUAL SPEED VARIATOR-CLUTCH UNIT Install drive belt (A). 07028168 Install ﬁxed primary pulley (G). Apply threadlocker to nut (D) and ﬁt nut complete with washer. Tighten nut (D) using a pneumatic nut runner set to the prescribed tightening torque. Cs-N * m 59 ±...
Page 77: Disassembling The Clutch
WORKSHOP MANUAL SPEED VARIATOR-CLUTCH UNIT Disassembling the clutch Unscrew locking nut (D). Withdraw cutch bell (A); now remove entire clutch unit and secondary pulley (B). DSCN8425 Using speciﬁc tool (C) compress clutch unit and secondary pulley (B). Undo nut (D). Release speciﬁc tool (C) and remove clutch unit;...
Page 78 125 - 160 cc...
Page 79: Removing The Secondary Pulley
WORKSHOP MANUAL SPEED VARIATOR-CLUTCH UNIT Remove rubber rings (M) from disk (L). 07028171 Removing the secondary pulley Remove pulley side retainer (A). 07028172 125 - 160 cc...
Page 80 WORKSHOP MANUAL SPEED VARIATOR-CLUTCH UNIT Remove guide pin (B) complete with roller (C); remove mobile secondary pulley (E). Check that guide pin (B) and roller (C) are not damaged or worn. 07028173 Remove oil seal (F) and O-rings (G) from mobile secondary pulley (ﬁt new oil seal and O-rings at time of assembly).
Page 81: Checks
WORKSHOP MANUAL SPEED VARIATOR-CLUTCH UNIT Checks Clutch bell Check clutch bell (L) for signs of damage or excessive wear. Measure inside diameter of clutch bell. Service limit: 125 mm 07028175 Clutch linings Check clutch linings (M) for signs of wear or damage. Service limit: 2,75 mm 07028176 125 - 160 cc...
Page 82: Variator Contrast Spring
WORKSHOP MANUAL SPEED VARIATOR-CLUTCH UNIT Variator contrast spring Check that variator contrast spring (N) is not weakened or broken. Measure spring length. Service limit: 140 mm 07028176 Fixed secondary pulley Check that ﬁxed secondary pulley (A) is not worn or damaged. Measure ﬁxed secondary pulley outside diameter.
Page 83: Mobile Secondary Pulley
WORKSHOP MANUAL SPEED VARIATOR-CLUTCH UNIT Mobile secondary pulley Check that mobile secondary pulley (B) is not worn or damaged. Measure inside diameter of secondary pulley. Service limit: 34.06 mm 07028179 125 - 160 cc...
Page 84: Assembling The Clutch
WORKSHOP MANUAL SPEED VARIATOR-CLUTCH UNIT Assembling the clutch Before assembling, degrease sliding surface of fixed secondary pulley, outer part of clutch and inner part of pulleys assy. Degrease and clean surface of mobile secondary pulley (A) in area of drive belt contact. Grease lip and ﬁt oil seal (B) with lip on side of internal surface of mobile secondary pulley.
Page 85 WORKSHOP MANUAL SPEED VARIATOR-CLUTCH UNIT Install mobile secondary pulley (A) on ﬁxed secondary pulley (D). Grease guide pin (E) and roller (F) before installing ﬁxed secondary pulley. 07028182 Fit pulley side retainer (G) on mobile secondary pulley (A). 07028183 125 - 160 cc...
Page 86 WORKSHOP MANUAL SPEED VARIATOR-CLUTCH UNIT Fit rubber rings (A) on disk (B). 07028184 Fit clutch shoes (C) and clutch shoe contrast springs (D). NOTE Pay attention to direction of assembly of clutch shoe contrast spring (D). 07028185 125 - 160 cc...
Page 87 125 - 160 cc...
Page 88: Installing The Clutch Bell
WORKSHOP MANUAL SPEED VARIATOR-CLUTCH UNIT Installing the clutch bell Insert clutch unit and secondary pulley (A) on shaft. Insert clutch bell (B) and tighten nut (D). Tighten nut (D) using a pneumatic nut runner set to the prescribed tightening torque. Cs-N * m 53 ±...
Page 89: Final Drive Gears
WORKSHOP MANUAL FINAL DRIVE GEARS Transmission Oil capacity For oil change 0,15 l For disassembly 0,15 l Recommended transmission oil SAE10W-40/SF grade Tightening torques Level/drain plug 22 N*m (± 15%) 125 - 160 cc...
Page 90: Final Drive Exploded View
WORKSHOP MANUAL FINAL DRIVE GEARS Final drive exploded view 1) Pulley shaft 2) Pulley shaft bearing 3) Reduction gear shaft 4) Intermediate gear 5) Washer 6) Intermediate gear bearing 7) Output shaft 8) Output shaft oil seal 9) Output shaft bearing 10) Transmission cover gasket 11) Transmission cover 12) Locating dowel...
Page 91: Removing The Transmission Cover
WORKSHOP MANUAL FINAL DRIVE GEARS Removing the transmission cover Remove clutch unit. Unscrew oil drain plug and allow all oil to ﬂow out. NOTE Dispose of spent oil in compliance with local legislation. Undo screws (V 07028187 Remove transmission cover (A) Remove locating dowels (B) and gasket (C).
Page 92 WORKSHOP MANUAL FINAL DRIVE GEARS Remove output shaft (D). Remove reduction gear shaft (E) and intermediate gear (F). 07028189 Remove thrust washer (G). 07028190 125 - 160 cc...
Page 93: Remove Pulley Shaft
WORKSHOP MANUAL FINAL DRIVE GEARS Remove pulley shaft Strike end (A) of pulley shaft with plastic mallet and extract main shaft. Check pulley shaft and bearings for wear or damage. Renew parts if necessary. 07028191 Transmission cover checks Turn inner races of bearings (B, C and D) of transmission cover (E) and clutch side engine casing;...
Page 94 WORKSHOP MANUAL FINAL DRIVE GEARS Check for possible damage or abrasion in transmission case and clutch side engine casing bearing seats (B, C and D). 07028193 Check output shaft (E) and its bearings for wear and damage. Renew bearings if necessary. Check reduction gear shaft (F), its bearings, and intermediate gear (G), for wear or damage.
Page 95: Removal And Refitting Of Transmission Cover Bearings And Oil Seal
WORKSHOP MANUAL FINAL DRIVE GEARS Removal and reﬁtting of transmission cover bearings and oil seal Remove output shaft oil seal (A) from transmission cover. 07028195 Remove output shaft bearing (B) by means of a puller. Use a puller and perform removal procedure in reverse to reassemble. 07028196 125 - 160 cc...
Page 96 WORKSHOP MANUAL FINAL DRIVE GEARS Remove pulley shaft bearing (C) and reduction gear shaft bearing (D) from transmission cover side, utilising puller (E). Insert new pulley shaft bearing (C) correctly, with punched side facing upwards, in seat in transmission cover, and drive it fully home. 07028197 Repeat same procedure also to install reduction gear shaft bearing (D).
Page 97: Removal And Refitting Of Clutch Side Engine Casing Bearings And Oil Seals
WORKSHOP MANUAL FINAL DRIVE GEARS Lubricate lip of new oil seal (F) of output shaft and insert with lip facing transmission cover interior. Fit oil seal so that it is straight with respect to hole; take care not to cover breather hole. 07028195 Removal and reﬁtting of clutch side engine 07028187...
Page 98: Installing The Transmission Gears
WORKSHOP MANUAL FINAL DRIVE GEARS Insert new pulley shaft bearing (B) correctly, with punched side facing upwards, in seat in clutch side casing, and drive it fully home. Repeat same procedure also to ﬁt output shaft bearing (C) and reduction gear shaft bearing (D).
Page 99: Installing The Transmission Cover
WORKSHOP MANUAL FINAL DRIVE GEARS Installing the transmission cover Fit clearance washer (A). 07028200 Fit intermediate gear (B) and reduction gear shaft (C) in transmission cover; ensure thrust washer is ﬁtted on reduction gear shaft. Fit output shaft (D). 07028201 125 - 160 cc...
Page 100 WORKSHOP MANUAL FINAL DRIVE GEARS Position gasket (E) and insert locating dowel (F). Mount transmission cover (G) to clutch side engine casing. 07028202 Insert screws (V ); tighten to prescribed torque. Cs-N * m 22 ± 15% Reassemble clutch unit. Fill transmission case with oil.
Page 101: Flywheel Cover, Flywheel Magneto, Water Pump
WORKSHOP MANUAL FLYWHEEL COVER, FLYWHEEL MAGNETO, WATER PUMP • Flywheel cover, ﬂywheel magneto assy and ﬂywheel must be disassembled with cold engine. • Flywheel cover can be removed without dropping engine from scooter. • Flywheel magneto can be removed without dropping engine from scooter. Tightening torques Flywheel magneto nut tightening 59 N*m ±...
Page 102: Exploded View Of Water Pump
WORKSHOP MANUAL FLYWHEEL COVER, FLYWHEEL MAGNETO, WATER PUMP Exploded view of water pump 1) Snap ring 2) Bearing 3) Water pump shaft 4) Bearing 5) Water pump oil seal 6) Water pump gland 7) Thrust washer 8) Water pump impeller 9) Locating dowel 10) Water pump gasket 11) Water pump cover...
Page 103: Exploded View Of Flywheel Cover
WORKSHOP MANUAL FLYWHEEL COVER, FLYWHEEL MAGNETO, WATER PUMP Exploded view of ﬂywheel cover 1) Locating dowel 2) Flywheel cover 3) Oil breather union 4) Gasket 5) Oil dipstick 6) O-Ring gasket 7) Oil ﬁlter 8) Oil ﬁlter spring 11 14 9) O-Ring gasket 10) Blank insert 11) Gasket...
Page 104: Removing The Flywheel Cover
DSCN8390 DSCN8391 125 - 160 cc...
Page 105: Removing The Flywheel Magneto
WORKSHOP MANUAL FLYWHEEL COVER, FLYWHEEL MAGNETO, WATER PUMP Undo screws (V Remove ﬂywheel cover (E). DSCN8391 Removing the ﬂywheel magneto Remove: • Oil ﬁtting (F) and its spring (G). • Locating dowel (L) and ﬂywheel cover gasket (M). • Starter motor relay gear (N) and its shaft (P). 07028204 125 - 160 cc...
Page 106: Removing The Freewheel Gear
WORKSHOP MANUAL FLYWHEEL COVER, FLYWHEEL MAGNETO, WATER PUMP Remove ﬂywheel magneto (A) using puller (D). 07028205 Removing the freewheel gear Remove bolt (V), remove retainer (B) and extract starter crown wheel (C). 07028206 125 - 160 cc...
Page 107: Removing The Stator/Pick-Up Assy
WORKSHOP MANUAL FLYWHEEL COVER, FLYWHEEL MAGNETO, WATER PUMP Removing the stator/pick-up assy Undo screws (VA ) and (VB ) and remove stator (A) and pick-up (B). Remove circlip (C). 07028207 Removing the water pump impeller Remove water pump impeller (D) by unscrewing it in clockwise direction.
Page 108: Installing The Water Pump
WORKSHOP MANUAL FLYWHEEL COVER, FLYWHEEL MAGNETO, WATER PUMP Installing the water pump Assembly procedure • Fit bearing (A) on pump shaft (B) then ﬁt shaft in ﬂywheel cover. • Fit bearing (C) on pump shaft (B) and secure with circlip (D). •...
Page 109: Installing The Stator/Pick-Up Assy
WORKSHOP MANUAL FLYWHEEL COVER, FLYWHEEL MAGNETO, WATER PUMP Install following components in ﬂywheel cover (A): • Inspection cap (B) and relative seal. • Dipstick (C). • Oil ﬁlter assy (D). • Drain plug (E) and relative washer. DSCN8391 Installing the stator/pick-up assy Install stator (F) and pick-up (G) and tighten screws (VA ) and (VB respectively.
Page 110: Installing The Freewheel Gear And Rotor
WORKSHOP MANUAL FLYWHEEL COVER, FLYWHEEL MAGNETO, WATER PUMP Fit cable grommets in seat (A), inserting ﬁrst number 1 then number 2. Apply sealant. 07028208 Installing the freewheel gear and rotor Install freewheel gear (B) in the ﬂywheel side engine casing (C), position restraint (D) and tighten screw (V).
Page 111 WORKSHOP MANUAL FLYWHEEL COVER, FLYWHEEL MAGNETO, WATER PUMP Install rotor (E) and tighten nut (D) to prescribed torque value; insert oil ﬁtting (F) and relative spring. Cs-N * m 59 ± 15% Install double intermediate gear (G) with relative shaft (L). Fit locating dowel (M) and ﬂywheel cover gasket (N).
Page 112: Installing The Flywheel Cover
WORKSHOP MANUAL FLYWHEEL COVER, FLYWHEEL MAGNETO, WATER PUMP Installing the ﬂywheel cover Install ﬂywheel cover (A), tighten screws (V ) working alternately at opposite corners in two or three passes. Cs-N * m 12 ± 15% Pay attention to correct pump shaft timing. DSCN8391 Fit locating dowels, gasket and cover of pump (B) and tighten screws (VA and (VB...
Page 113 WORKSHOP MANUAL FLYWHEEL COVER, FLYWHEEL MAGNETO, WATER PUMP Fit water inlet hose (C) and breather hose (D). Fill cooling circuit. Fill engine with required oil quantity. DSCN8390 125 - 160 cc...
Page 114: Engine Casing, Crankshaft
WORKSHOP MANUAL ENGINE CASING, CRANKSHAFT Standard Service limit Connecting rod big end End play 0.160-0.304 mm 0.50 mm Radial play 0.005-0.017 mm 0.05 mm Crankshaft eccentricity — 0.10 mm Tightening torques Removable casing screws 12 N*m ± 15% Chain tensioner pin 13 N*m ±...
Page 115: Removing The Engine Casings
WORKSHOP MANUAL ENGINE CASING, CRANKSHAFT Removing the engine casings Unscrew pin (V) and extract chain guide (A). 07028211 Unscrew screws (V ) of clutch side engine casing (B). Place ﬂywheel side engine casing on a bench and withdraw clutch side engine casing (B).
Page 116: Crankshaft Checks
WORKSHOP MANUAL ENGINE CASING, CRANKSHAFT Remove gasket (C) and locating dowels (D). Remove oil seals (E) from engine casings. Do not prise with a screwdriver etc. in area of contact between casings if it proves difﬁcult to remove ﬂywheel side casing. Tap lightly with a plastic mallet and keep clutch side engine casing raised.
Page 117 WORKSHOP MANUAL ENGINE CASING, CRANKSHAFT Measure radial play of connecting rod big end (A). Service limit: 0.05 mm 07028215 Measure crankshaft eccentricity (B). Service limit: 0.10 mm 62 mm 80 mm 07028216 125 - 160 cc...
Page 118: Installing The Engine Casing
WORKSHOP MANUAL ENGINE CASING, CRANKSHAFT Measure connecting rod small end diameter (C). Service limit: 15.05 mm 07028217 Installing the engine casing Lubricate internal lip of new oil seal (A) and apply sealant to external side before installing in ﬂywheel side engine casing. Fit locating dowels (B) and gasket (C).
Page 119 WORKSHOP MANUAL ENGINE CASING, CRANKSHAFT Install complete connecting rod assy. Install chain guide (D) and pin (V). Tighten to prescribed torque. Cs-N * m 13 ± 15% Do not damage casing mating surfaces during installation procedures. 07028211 Join left and right casings. Tighten screws (V ) to prescribed torque.

This manual is also suitable for:

Centro 160

Malaguti Centro 125 Workshop Manual

Oil Pump Assy

Cylinder Head, Valves, Cylinder, Piston

Speed Variator-Clutch Unit

Final Drive Gears

Flywheel Cover, Flywheel Magneto, Water Pump

Engine Casing, Crankshaft

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Troubleshooting

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