53
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.
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 (see Honing Cylin-
der in this sub-section).
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.
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.
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.
3. Inspect the cylinder for pitting, scoring, scuffing, and
corrosion. If marks are found, repair the surface
using a #320 grit ball hone.
NOTE: To produce the proper 60° cross-hatch
pattern, use a low RPM drill (600 RPM) at the rate
of 30 strokes per minute. If honing oil is not avail-
able, use a lightweight petroleum-based oil. Thor-
oughly clean cylinder after honing using soap and
hot water. Dry with compressed air; then immedi-
ately apply oil to the cylinder bore. If the bore is
severely damaged or gouged, replace the cylinder.
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.
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.