Honda CRF450R Owner's Manual page 44

4. SERVICE AND MAINTENANCE
Cam Shaft Holder Assembly/Cylinder Head/Cylinder/
Piston/Piston Pin/Piston Ring Inspection
We recommended you consult the Service Manual or
your authorized Honda dealer for correct Service Limit
measurements.
42
Piston Ring Installation.
Clean the piston ring groove
Apply engine oil to the piston rings and install the pis-
ton rings.
CAUTION:
Do not damage the piston ring by spreading the
•
ends too far.
Do not damage the piston during piston ring instal-
•
lation.
NOTE:
• To install the oil ring, install the spacer first, then
install the side rails.
• Install the top ring on the piston with the marking
side facing up.
After installing the rings they should rotate freely, with-
out sticking.
Space the ring end gaps 180 degrees apart between
top ring and upper side rail.
Space the ring end gaps 120 degrees apart between
upper side rail, spacer and lower side rail.