3-15
3
2. Measure the corresponding piston diameter at a
point 15 mm above the piston skirt at a right angle
to the piston-pin bore. Subtract this measurement
from the measurement in step 1. The difference
(clearance) must be within specifications.
Installing Piston Rings
1. Install ring expander (4) in the bottom groove of
the piston; then install the thin oil rings (3) over
the expander making sure the expander ends do
not overlap. Stagger the end gaps of the upper and
lower thin oil rings according to the illustration.
ATV-1085B
NOTE: Note the direction of the exhaust side of
the piston (5) for correct ring end gap orientation.
2. The ring with the orientation mark (MTOP or
TOP) should be installed in the second (middle)
groove and the ring with the orientation mark (M
or O) should be installed in the first (top) groove.
ATV-1024A
ATV-1024B
CYLINDER/CYLINDER HEAD
ASSEMBLY
NOTE: If the cylinder/cylinder head assembly
cannot be trued, they must be replaced.
Cleaning/Inspecting Cylinder Head
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
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.
! CAUTION
Incorrect installation of the piston rings will result in
engine damage.
! CAUTION
The cylinder head studs must be removed for this
procedure.
! CAUTION
Water or parts-cleaning solvent must be used in
conjunction with the wet-or-dry sandpaper or dam-
age to the sealing surface may result.
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