Yamaha MX360 - Checking the Crankcase; Checking the Piston Pin

PISTON, CAMSHAFT, CRANKCASE, AND CRANKSHAFT
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ENGINE
CHECKING THE CRANKCASE
1.
Check:
• Crankcase
Damage  Re
place.
• Bearing
Noise/wear/rotational failure  Re
place.
CHECKING THE PISTON PIN
1.
Check:
• Piston pin
Blue discoloration/grooves  Replace the piston
pin and then check the lubrication system.
2.
Measure:
• Piston pin hole inside diameter “a”
Out of specification  Replace.
3.
Measure:
• Piston pin diameter “a”
Out of specification  Replace.
4.
Check:
• Check that the piston pin enters smoothly into the
piston pin hole.
TIP
If the piston pin fits too tight into the piston, check the pis-
ton pin hole. If there is any protrusion, use a knife or
scraper to gently remove it so that piston pin can be
pushed in smoothly with your fingers.
a
Piston pin hole inside diameter:
20.004–20.015 mm (0.7872–0.7874 in)
Limit:
20.045 mm (0.7892 in)
a
Piston pin diameter:
19.995–20.000 mm (0.7872–0.7874 in)
Limit:
19.975 mm (0.7864 in)