48
ROV1-044
16. Repeat step 15 for the other piston.
Servicing Top-Side
Components
MEASURING VALVE/TAPPET
CLEARENCE
1. Rotate the engine two full revolutions.
NOTE: Rotating the engine two full revolutions will
ensure that any oil trapped in the tappet/shim is
purged to maintain an accurate clearance reading.
2. Rotate the engine until the camshaft lobe of the valve
being measured is directly away from the tappet.
3. Using an appropriate thickness gauge, measure and
record the intake and exhaust valve clearance of the
cylinder that is on the compression stroke; then rotate
the engine 360° and measure and record the valve
clearance of the other cylinder. Valve clearance must
be within specifications.
KC534A
4. To select the correct replacement shim for an out-of-
specification clearance, note the three-digit number on
the surface of the existing shim; then refer to the
appropriate Tappet Shim Selection Table (Exhaust or
Intake) on the following pages and use this procedure:
A. Find the Measured Tappet Clearance (from step 3)
in the left-side vertical column of the table.
B. Find the Present Shim Size (three-digit-number) at
the top-side horizontal column of the table.
C. Match the clearance in the vertical column with the
present shim size to obtain the recommended
replacement shim.
Cleaning/Inspecting Valve Cover
NOTE: If the valve cover cannot be trued, the cylin-
der head assembly must be replaced.
1. Wash the camshaft holder in parts-cleaning solvent.
2. Place the camshaft holder on the Surface Plate cov-
ered with #400 grit wet-or-dry sandpaper. Using light
pressure, move the camshaft holder 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 camshaft holder in a
figure eight motion until a uniform bright metallic fin-
ish is attained.
WT581
VALVE ASSEMBLY
When servicing valve assembly, inspect valve seats, valve
stems, valve faces, and valve stem ends for pits, burn
marks, or other signs of abnormal wear.
NOTE: Whenever a valve is out of tolerance, it must
be replaced.
AT THIS POINT
To service center crankcase components only, proceed
to Removing Left-Side Components.
Valve Clearance (Cold)
15°-25° C
(59°-77° F)
Intake: 0.16 mm (0.006 in.)
Exhaust: 0.22 mm (0.009 in.)
CAUTION
Do not remove an excessive amount of the sealing sur-
face or damage to the camshaft will result. Always check
camshaft clearance when resurfacing the valve cover.
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.