79
CC144D
2. Insert each valve into its original location.
3. Install the valve springs with the painted end of the
spring facing away from the cylinder head.
NOTE: If the paint is not visible, install the ends of
the springs with the closest wound coils toward the
head.
ATV-1011A
4. Place a spring retainer over the valve springs; then
using the valve spring compressor, compress the valve
springs and install the valve cotters.
PISTON ASSEMBLY
NOTE: Whenever a piston or pin is out of tolerance,
it must be replaced.
Removing Piston Rings
1. Starting with the top ring, slide one end of the ring out
of the ring-groove.
2. Remove each ring by working it toward the dome of
the piston while rotating it out of the groove.
CC400D
Cleaning/Inspecting Piston
1. Take an old piston ring and snap it into two pieces;
then grind the end of the old ring to a 45° angle and to
a sharp edge.
2. Using the sharpened ring as a tool, clean carbon from
the ring-grooves.
3. Using a non-metallic carbon removal tool, remove any
carbon buildup from the dome of the piston.
4. Inspect the piston for cracks in the piston pin, dome,
and skirt areas.
5. Inspect the piston for seizure marks or scuffing.
6. Inspect the perimeter of each piston for signs of exces-
sive “blowby.” Excessive “blowby” indicates worn
piston rings or an out-of-round cylinder.
Measuring Piston-Ring End Gap
(Installed)
1. Place each compression ring in the wear portion of the
cylinder. Use the piston to position each ring squarely
in the cylinder.
2. Using a feeler gauge, measure each piston-ring end gap.
Acceptable ring end gap must be within specifications.
CC280D
CAUTION
Improper cleaning of the ring-grooves by the use of the
wrong type of ring-groove cleaner will result in severe
damage to the piston.
