Cylinder And Piston - Jianshe JS125-6B Maintenance Manual

Cylinder and piston

1. Clean
Carbon deposit
(From the top of piston
2. Check
Piston side wall
Wear, scratching and damage
3. Check
Cylinder wall
Wear or scuffing
replace
4. Measurement
Piston-to-cylinder clearance
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Measuring steps
1. Measure the cylinder bore C with a bore gauge.
The position of D3,D4 (40mm distance from the top
of cylinder)
Note
Measure the cylinder bore in the two directions, one
parallels to the crankcase, one squares to the crankcase,
and then demand an average value.
Cylinder inside diameter standard:
Out of specification
2. Measure the piston
Measure the piston skirt diameter with micrometer
calipers, and measure it at the distance of 5.0 mm
away from the bottom margin of the piston.
Piston outside diameter standard:
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73
and ring groove
Replace
Bore cylinder once more or
54.024 54.056 mm
Replace
53.997 54.029 mm
ENGINE
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