Yamaha KT100SEC - ENGINE PARTS INSPECTION - PISTON AND RING; INSPECTING PISTON AND RING GROOVES; MEASURING PISTON DIAMETER; CHECKING PISTON PIN FREE PLAY

4-11
ENG
CHECKINGTHEENGINEPARTS
1.Inspect:
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Pistoncrowncarbondeposits
Useascraper.
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Ringgroovecarbondeposits
Useausedpistonring.
Wear/Scratches/Damage→Replace.
2.Measure:
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Pistondiameter
Micrometer
10 mm (0.39 in) from the piston bottom
edge.
CHECKINGTHEPISTONANDPISTONPIN
1.Measure:
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Endgap
Thicknessgauge
Insert a ring into the cylinder and push it
approximately10mm(0.39in)intothecylinder.
CHECKINGTHEPISTONRING
Standardpistondiameter
51.970〜51.990mm
Endgaplimit
0.5mm
3.Check:
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Freeplay(Whenthepistonpinisinplace
inthepiston.)
Thereshouldbenonoticeablefortheplay.
Freeplayexists→Replacepistonpinand/or
piston.
4.Inspect:
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Checkthefreeplaywhenthepistonpinand
bearingareinplaceintheconnectingrod.
Freeplayexists→Replacepistonpinand/or
smallendbearing.
Outofspecification→Replace