Service manual

3. Inspect breather return pipe. If cracked/leaked/damaged, replace.

Piston

Measure piston outside diameter at the specified measuring point. If out of specification, replace.

Piston diameter: 58.950～58.965mm

Measuring point○

: 10mm

Cylinder bore

1. Measure cylinder bore separately at measuring point ○1, ○2, ○3 . At each point, measure the

cylinder bore at places D1, D3, D5 parallel to the crankcase and at places D2, D4, D6 vertical to

the crankshaft.

②

③

①

D1&D2

D3&D4

D5&D6

Measuring point height:

○

100mm；

○

40mm；

○

70mm

Cylinder bore: 59～59.02mm

Limit size: 59.10mm

2. Calculate taper limit and round limit. If out of specification, replace crankcase.

Taper limit: 0.08mm(D1-D5, D2-D6)

Round limit: 0.05mm(D2-D1, D6-D5)

Piston pin diameter

Measure piston pin outside diameter. If out of specification, replace the piston pin.

Piston pin outside diameter: 12.995～13.000mm

Piston ring

1. Push the piston ring parallel with the piston crown into the specified measuring point of the

cylinder (10mm from conjunction surface).

2. Measure end gap by space gauge. If out of specification, replace the piston ring.

End gap (installed) / limit size: Top ring 0.10～0.20mnm/0.4mm

2nd ring 0.25～0.40mm/0.6mm

Oil ring 0.2～0.7mm/0.9mm

3. Install piston ring to piston, and measure side clearance between piston ring and its slot by

clearance gauge. If out of specification, replace the piston ring.

Side clearance: Top ring 0.04～0.08mnm

2nd ring 0.02～0.06mm

Camshaft decompressor

1. Inspect camshaft decompressor, gear, and weight. If gear is worn/damaged/cracked, replace.