Arctic Cat Sno Pro 120 2011, Service Manual

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ZJ046A
31. Remove the oil separator plates for the lower crank-
case half and account for the eight Allen-head cap
screws.
ZJ047A
32. Remove the Allen-head cap screws securing the pis-
ton cooling jets to the upper crankcase half; then
remove the jets and account for the O-rings.
ZJ054A
ZJ035

NOTE: For assembling purposes, ensure the ori-
fices in the piston cooling jets are cleared of any dirt
and/or debris.
ZJ055A
Servicing Components

NOTE: Critical engine specifications are located in
Section 1 of this manual.
Thoroughly clean all non-electrical components in parts-
cleaning solvent; then remove any carbon buildup from
the cylinder head and piston dome.
Visually inspect all engine components for wear or dam-
age.

NOTE: Whenever a part is worn excessively,
cracked, or damaged in any way, replacement is nec-
essary.
PISTON ASSEMBLY

NOTE: Oversized pistons are available allowing the
cylinder to be bored oversized.

NOTE: Whenever a piston, rings, or pins are out of
tolerance, they must be replaced.
Cleaning/Inspecting Piston
1. Using a non-metallic carbon removal tool, remove
any carbon buildup from the dome of the piston.
2. Inspect the piston for cracks in the piston pin, dome,
and skirt areas.
3. Inspect the piston for seizure marks or scuffing.

NOTE: If seizure marks or scuffing is detected, the
piston must be replaced.
4. Inspect the perimeter of each piston for signs of
excessive “blowby.” Excessive “blowby” indicates
worn piston rings 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.
2. Remove each ring by working it toward the dome of
the piston while rotating it out of the groove.
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