Arctic Cat XC 450 2016 Service Manual page 40

CAUTION
Incorrect installation of the piston rings will result in
engine damage.
CYLINDER/CYLINDER HEAD
ASSEMBLY
NOTE: If the cylinder/cylinder head cannot be

trued, they must be replaced as an assembly.
Cleaning/Inspecting Cylinder Head
CAUTION
The cylinder head studs must be removed for this pro-
cedure.
1. Using a non-metallic carbon removal tool, remove
any carbon buildup from the combustion chamber
being careful not to nick, scrape, or damage the com-
bustion 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 covered
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 assem-
bly by continuing to move the cylinder head in a fig-
ure eight motion until a uniform bright metallic
finish is attained.
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.
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
Cleaning/Inspecting Cylinder
1. Wash the cylinder in parts-cleaning solvent.
2. Inspect the cylinder for pitting, scoring, scuffing,
warpage, and corrosion. If marks are found, repair
the surface using a cylinder hone.
3. Place the cylinder on the surface plate covered with
#400 grit wet-or-dry sandpaper. Using light pressure,
move the cylinder 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 continu-
ing to move the cylinder in a figure eight motion
until a uniform bright metallic finish is attained.
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.
CC129D
Inspecting Cam Chain Guide
1. Inspect cam chain guide for cuts, tears, breaks, or
chips.
2. If the chain guide is damaged, it must be replaced.
Measuring/Honing Cylinder
1. Using a slide gauge and a dial indicator or a snap
gauge, measure the cylinder bore diameter in three
locations from top to bottom and again from top to
bottom at 90° from the first measurements for a total
of six measurements. The trueness (out-of-round-
ness) is the difference between the highest and low-
est reading. Maximum trueness (out-of-roundness)
must not exceed specifications.
CC127D
2. Wash the cylinder in parts-cleaning solvent.
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