11. CRANKCASE/CRANKSHAFT

11-0

VITALITY 50

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CRANKCASE/CRANKSHAFT__________________________________________________________________________________

SERVICE INFORMATION........................................................ 11- 3CRANKCASE/CRANKSHAFT (2-STROKE)............................... 11- 4CRANKCASE/CRANKSHAFT (4-STROKE)............................... 11-10

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11. CRANKCASE/CRANKSHAFT

11-1

VITALITY 50

(2-STROKE)

Torque: 0.8_ 1.2kg-m

11. CRANKCASE/CRANKSHAFT

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VITALITY 50

(4-STROKE)

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VITALITY 50

SERVICE INFORMATION

GENERAL INSTRUCTIONS

• This section covers crankcase separation to service the crankshaft. The engine must be removedfor this operation.

• The following parts must be removed before separating the crankcase.−Cylinder head (Chapter 6 (2-stroke))−Cylinder/piston (Chapter 7)−Drive and driven pulleys (Chapter 9)−A.C. generator (Chapter 8)

SPECIFICATIONS (2-Stroke)

Item Standard (mm) Service Limit (mm)Connecting rod big end side clearance 0.6

Crankshaft Connecting rod big end radial clearance 0.04

Run out A/B 0.1/0.15

SPECIFICATIONS (4-Stroke)

Item Standard (mm) Service Limit (mm)Connecting rod small end free play 0.05_ 0.4 0.6

Crankshaft Connecting rod big end radial clearance 0_ 0.008 0.05

Run out 0.10

TORQUE VALUESCrankcase bolt 0.8_ 1.2kgf-mCam chain tensioner slipper bolt 0.8_ 1.2kgf-m (4-Stroke)

SPECIAL TOOLS (2-stroke)

Crankcase puller E026Universal bearing puller E030Crankshaft install tool E016Crankcase assembly tool E024Oil seal and bearing install tool E014

TROUBLESHOOTING

Abnormal engine noise• Excessive crank journal bearing play• Excessive crankpin bearing play• Excessive transmission bearing play

11. CRANKCASE/CRANKSHAFT

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VITALITY 50

CRANKCASE/CRANKSHAFT

(2-STROKE)SEPARATIONRemove the crankcase attaching bolts.

Attach the crankcase puller on the rightcrankcase and remove the right crankcasefrom the left crankcase.

Crankcase puller E026

CRANKSHAFT REMOVAL

Attach the crankcase puller on the leftcrankcase and remove the crankshaft fromthe left crankcase.

Crankcase puller E026

When removing the crankshaft, do itslowly and gently.

°Ø

Crankcase Puller

Crankcase Puller

Bolt

Special

Special

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Remove the remaining bearing on thecrankshaft side using the universal bearingpuller.

Crankshaft bearing puller E030

CRANKSHAFT INSPECTION

Measure the connecting rod big end sideclearance.Service Limit: 0.6mm replace if over

Measure the connecting rod big end radialclearance at two points in the X and Ydirections.Service Limit: 0.04mm replace if over

When separating the crankcase, the oilseals must be removed. Replace the oilseals with new ones.

°Ø

Universal Bearing Puller

Special

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VITALITY 50

Measure the crankshaft runout.

Service Limit

A B

0.150mmreplace if over

0.100mmreplace if over

Check the crankshaft bearings for excessiveplay. The bearings must be replaced if theyare noisy or have excessive play.

CRANKSHAFT INSTALLATION

Wash the crankshaft in cleaning solvent andthen check for cracks or other faults.

•After check, apply clean engine oil toall moving and sliding parts.

• Remove all gasket material from thecrankcase mating surfaces. Dress anyroughness or irregularities with an oilstone.

°Ø

Axial

PlayPlay

Radial

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Drive a new crankshaft bearing into theright crankcase.

Oil seal & bearing install E014

The distance between the left crankcase oilseal and crankcase surface is about 1.0mm.

Drive a new crankshaft bearing into the leftcrankcase.

Oil seal & bearing install E014

The distance between the right crankcase oilseal and crankcase surface is about 12.5±0.5mm.

Bearing Outer Driver Handle A

Bearing Outer Driver Handle A

Bearing Outer Driver, 37x40mmBearing Driver Pilot, 17mm

Bearing Outer Driver, 42x47mmPilot, 20mm

Special

Special

When installing the oil seal, be careful topress it with even force.

°Ø

Oil Seal

1.0mm

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ASSEMBLY

Install the dowel pins and a new gasket tothe crankcase mating surface.

Assemble the crankcase halves.

Crankcase assembly tool E024

Dowel Pins

Crankcase Assembly Tool

Crankcase Assembly Tool

Special

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VITALITY 50

Install and tighten the crankcase bolts in acrisscross pattern in several steps.

Bolt

After assembly, check the crankshaftfor smooth operation.

°Ø

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VITALITY 50

CRANKCASE/CRANKSHAFT

(4-STROKE)

REMOVAL

Remove nuts and take out the bolts fromcenter stand.

Remove spring and center stand fromcrankcase.

Remove the crankcase attaching bolt.Separate the left and right crankcase halves.

Nuts/Bolts

Spring

Bolt

Center Stand

• Do not damage the crankcasegasket surface.• Never use a driver to pry the

crankcase mating surfaces apart.

°Ø

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Remove the crankshaft from the leftcrankcase.

Remove the cam chain.Remove the gasket and dowel pins.

Clean off all gasket material from thecrankcase mating surfaces.

Dowel Pins

Gasket

RadialAxial

Avoid damaging the crankcase matingsurfaces.

°Ø

Crankshaft

Cam Chain

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CRANKSHAFT INSPECTIONMeasure the connecting rod small end I.D.Service Limit: 13.06 mm replace if over

Measure the connecting rod small end freeplay (A).Out of specification (0.05 ~ 0.4 mm) _Replace the crankshaft.

Measure the crankshaft run out (B).Service Limit: 0.10mm replace if over

Measure the connecting rod big end sideclearance (C).Service Limit: 0.05mm replace if over

Measure the crank width (D).Out of specification (42.2 ~ 42.15 mm) _Replace the crankshaft.

Turn the crankshaft bearings and check forexcessive play.Measure the crankshaft bearing play.Service Limit: Axial : 0.20mm replace if over Radial : 0.05mm replace if over

A

B B

CD

Play

Play

RadialAxial

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VITALITY 50

CRANKCASE/BALANCERINSTALLATIONInstall the cam chain into the left crankcase.

Install the dowel pins and a new gasketonto the left crankcase.

Install the crankshaft into the left crankcase.

Install the right crankcase.Tighten the crankcase attaching bolt.Torque: 0.8~1.2kgf-m

Bolt

Place the right crankcase over thecrankshaft and onto the left crankcase.

°Ø

When installing the crankshaft, be carefulnot to damage the oil seal.

°Ø