Arctic Cat ATV 250 Utility 2009, Руководство по обслуживанию

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KM710A
Removing Valves
„
NOTE: Keep all valves and valve components as
a set. Note the original location of each valve set
for use during installation. Return each valve set
to its original location during installation.
1. Using a valve spring compressor, compress the
valve springs and remove the valve cotters.
Account for an upper spring retainer.
KM717A
2. Remove the valve seal, valve springs, and the lower
remaining spring seat. Discard the valve seal.
„
NOTE: The valve seals must be replaced.
3. Invert the cylinder head and remove the valves.
Measuring Valve Stem/
Valve Guide Clearance
1. Using a micrometer, measure the valve stem outside
diameter; then using a suitable snap gauge and
micrometer, measure the valve guide inside diameter
2. Acceptable clearance must be within specifications.
Inspecting Valve Face
Inspect the valve face for pitting, grooving, or discol-
oration. Replace any valve that is damaged.
CYLINDER HEAD ASSEMBLY
„
NOTE: If the cylinder head cannot be trued, it
must be replaced.
Cleaning/Inspecting Cylinder Head
1. Using a non-metallic carbon removal tool, remove
any carbon build-up from the combustion chamber
making sure not to nick, scrape, or damage the
combustion chamber or the sealing surface.
2. Inspect the spark plug hole for any damaged
threads. Repair damaged threads using a
“heli-coil” insert.
3. Place the cylinder head on the surface plate cov-
ered with #400 grit wet-or-dry sandpaper. Using
light pressure, move the cylinder head in a figure
eight motion. Inspect the sealing surface for any
indication of high spots. A high spot can be noted
by a bright metallic finish. Correct any high spots
before assembly by continuing to move the cylin-
der head in a figure eight motion until a uniform
bright metallic finish is attained.
Measuring Cylinder Head
Distortion
1. Remove any carbon buildup in the combustion
chamber.
2. Lay a straightedge across the cylinder head; then
using a feeler gauge, check the distortion factor
between the head and the straightedge.
3. Maximum distortion must not exceed specifications.
CC141D
Measuring Camshaft Lobe Height
1. Using a calipers, measure each cam lobe height.
! CAUTION
Water or parts-cleaning solvent must be used in con-
junction with the wet-or-dry sandpaper or damage to
the sealing surface may result.
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