Checking The Piston Pins And Small-End Bearings - Yamaha EK25BMH Service Manual

POWR
CRANKSHAFT AND CYLINDER BODY
CHECKING THE PISTON PINS AND
SMALL-END BEARINGS
1. Check:
• Piston pin
• Small-end bearing
Heat discoloration → Replace.
Damage/scratches → Replace.
2. Measure:
• Piston pin outside diameter
(use an outside micrometer)
Out of specification → Replace.
Outside micrometer
90890-03006
Piston pin outside diameter
19.895 – 19.900 mm
(0.7833 – 0.7835 in)
3. Measure:
• Piston pin boss inside diameter
(use an inside micrometer)
Out of specification → Replace.
Inside micrometer
90890-03010
Piston pin boss inside diameter
19.904 - 19.915 mm
(0.7836 - 0.7841 in)
5-32
E