Piston Pin Inspection; Small End Bearing Surface Inspection; Piston/Piston Ring Installation - Honda Motorcycle Service Manual

PISTON PIN INSPECTION
Measure the piston pin O.D. at three points.
Replace the piston pin if the service limit is exceeded.
Calculate the piston pin-to-pin bore clearance by subtracting
the piston pin O.D. from the pin bore I.D.
SMALL END BEARING SURFACE INSPECTION
2-stroke Engines:
Install the needle bearing and piston pin in the connecting rod
small end and check for excessive play.
If the piston pin I.D. is over the service limit, the crankshaft
must be replaced. Measure the I.D. of the connecting rod small
end.
4-stroke Engines:
Measure the I.D. of the connecting rod small end
Replace the connecting rod or crankshaft assembly if the ser-
vice limit is exceeded.
PISTONIPISTON RING INSTALLATION
4-stroke Engines:
Clean the piston heads, ring lands and skirts.
Carefully install the piston rings onto the piston with the mark-
ings facing up.
NOTE
Be careful not t o damage the piston and rings during
assembly.
Do not confuse the top and second rings: The top ring is
chrome-coated and the second ring is not coated (black).
After installing the rings they should rotate freely,
without sticking.
Space the ring end gaps 120 degrees apart.
Space the side rail gaps 40 m m (1.6 in) or more apart as
shown.
4-STROKE ENGINE
/
2-STROKE ENGINE
MARK
I
10-8
Date of Issue: Sep., 1988
O
HONDA MOTOR CO., LTD.