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5. Remove the connecting rod bolts and connecting rod cover, remove the crankshaft, and
then remove the connecting rod and piston assembly.
6. Remove piston pin clamp spring with pliers, then remove the piston pin and piston.
7. Remove the oil seal, locating pin and bearing bush.
Piston
1. Measure the outside diameter of piston at the specified measuring point.
If it does not meet the specified value, replace it.
Diameter of piston: 80.938～80.950 mm
Measuring point○a : 14 mm
2. Check the inner diameter of piston pin. If it does not meet the specified value, replace it.
Inner diameter of piston pin seat: 18.004～18.015mm
Cylinder bore
1. Measure the piston outer diameter at specified measuring points○1 ○2 ○3 . At each measuring
point, measure the diameters parallel to the crankshaft directions D1, D3 and D5 and
perpendicular to the crankshaft directions D2, D4 and D6.
Height of measuring point: ○1 5 mm;
○2 35 mm;
○
3 94 mm
Cylinder bore: 81.000～81.012 mm
2. Calculate the taper limit and roundness limit. If it exceeds the specified value, replace
the crankcase.
Taper limit: 0.08 mm (D1-D5, D2-D6)
Roundness limit: 0.05 mm (D2-D1, D6-D5)
Outside diameter of piston pin
Check the outside diameter of piston pin; If it does not meet the specified value, replace it.
Outside diameter of piston pin: 17.991～18.000 mm
Piston ring
1. Push the piston ring into the cylinder in parallel with the piston to the specified
measuring point (10mm from the joint surface).
2. Measure the clearance of piston ring end face with a clearance gauge; If it does not meet
a
D
②
③
①
D1&D2
D3&D4
D5&D6
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