Arctic Cat ATV 250 Utility 2009, Руководство по обслуживанию

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3-12
ATV1013A
2. The lobe heights must not be less than minimum
specifications.
Inspecting Camshaft Bearing
Journal
1. Inspect the bearing journal for scoring, seizure
marks, or pitting.
2. If excessive scoring, seizure marks, or pitting is
found, the cylinder head assembly must be
replaced.
Measuring Rocker Arm/
Shaft Clearance
1. Using a dial calipers, measure the inside diameter
of the rocker arm; then measure the outside diame-
ter of the rocker arm shaft.
2. Acceptable clearance must not exceed specifications.
Installing Valves
1. Apply grease to the inside surface of the valve
seals; then place a lower spring seat and valve
guide seal over each valve guide.
2. Insert each valve into its original valve location.
3. Install the valve springs with the closest coils
toward the cylinder 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.
KM717A
PISTON ASSEMBLY
„
NOTE: Whenever a piston, rings, or pin 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.
Repair with #400 grit wet-or-dry sandpaper and
water or honing oil.
„
NOTE: If scuffing or seizure marks are too deep
to correct with the sandpaper, replace the piston.
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.
CC400D
2. Remove each ring by working it toward the dome
of the piston while rotating it out of the groove.
„
NOTE: If the existing rings will not be replaced
with new ones, note the location of each ring for
proper installation. When installing new rings,
install as a complete set only.
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