Arctic Cat 2015 XR Service Manual page 43

2. Insert each valve into its original valve 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.
4. Place a spring retainer over the valve springs; then
using the valve spring compressor, compress the
valve springs and install the valve keepers.
PISTON ASSEMBLY
NOTE: Whenever a piston, rings, or pin are out of
tolerance, they must be replaced.
Inspecting Piston
1. Inspect the piston for cracks in the piston pin, boss,
top, and skirt areas.
2. Inspect the piston for seizure marks or scuffing. If
piston is scored or galled, replace it with a new one.
3. Inspect the perimeter of each piston for signs of
"blowby" indicated by dark discoloration. "Blowby"
is caused by worn piston rings, excessive carbon in
ring grooves, or an out-of-round cylinder.
Removing Piston Rings
1. Starting with the top ring, slide one end of the ring
out of the ring-groove.
CC144D
2. Remove each ring by working it toward the top of
the piston while rotating it out of the groove.
NOTE: When installing new rings, install as a
complete set only.
Measuring Piston-Ring End Gap
(Installed)
1. Place each piston ring in the wear portion of the cyl-
ATV-1011A
inder. 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 not exceed speci-
fications.
CC132D
Measuring Piston Pin, Connecting
Rod Small End, and Piston-Pin Bore
1. Measure the piston pin outside diameter at each end
and in the center. If measurement does not meet
specifications, the piston pin must be replaced.
CC400D
CC995
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