(5) Bend ear of locknut (12), flat against
gear, unscrew and remove nut (11) while hold-
ing gear (10) stationary. Slide off nut (12)
and pull off gear (10). Remove Woodruff key
(13) from keyway on shaft.
(6) Remove thrust plate (14) after re-
moving two attaching screw and lockwasher
assemblies (15).
(16)
(7) Carefully slide camshaft
through front of cylinder and crankcase as-
sembly being careful not to scuff cams or
journals or bushings.
(8) Drive out bushings (17, 18, 19 and
20) only if in need of replacement.
b. Cleaning. Clean all parts in solvent and
dry with compressed air. Clean gear (10) with
wire brush and blow off with compressed air.
Use wire, if necessary, to clean deposits from
spacing.
inside guides (9). Clean oil holes in bushings
(17, 18, 19 and 20) with bristle brush and
(20) Install oil pump as outlined in para-
compressed air.
graph 6-9.
c. Inspection. Inspect gear (10) for exces-
(21) After replacing gear cover, insert
sive wear and broken or chipped teeth. Inspect
Woodruff key (5, fig. 6-11) in crankshaft and
thrust plate (14) for scoring and wear. In-
tap pulley (3) on crankshaft with soft hammer.
spect bushings (17, 18, 19 and 20) for exces-
Insert keyway plug (4) in keyway and tap
sive wear, scoring, and proper ID. Inspect cams
into position with hammer. Face of plug (4)
and journals on camshaft (16, fig. 6-23) for
should be flush with face of pulley (3).
scoring and excessive wear. Inspect oil pump
(22) Slide washer (2) on crankshaft, then
drive gear on camshaft for wear and scoring.
screw on starting jaw (1) after placing bar
Inspect valves for pitted or burned faces and
between bolts (13) on flywheel to hold crank-
warped or excessively worn stems. Inspect in-
shaft stationary. Tighten starting jaw (1)
serts (8, fig. 6-23 for pitted or burned seats
with large wrench.
and looseness. Inspect valve guides (9) for
6-11. Camshaft and Valve Assembly
wear. Check valve springs on spring tester to
a. Removal and Disassembly.
make sure minimum specifications listed in
(1) If camshaft and valve assembly is not
being removed in normal order of disassem-
bly, remove gear cover, cylinder head, oil pan
d. Repair. If bushings (17, 18, 19 and 20)
and valve chamber cover as outlined in para-
are scored or worn beyond allowable limits,
drive out and carefully drive in new bushings.
(2) Compress valve springs with a valve
Be careful to line up oil holes in bushings with
spring lifter and remove two locks (1, fig. 6-
oil holes in block. If camshaft (16) is scored
23) from each valve stem, when in closed posi-
or worn excessively or has worn or scored oil
tion, then remove retainers (2) and springs
pump drive gear, replace. Valves must be re-
(3) through va1ve tappet chamber and valves
faced or replaced. All valves having less than
(4) from top of cylinder and crankcase as-
50% margin thickness (outer edge of valve
sembly. Remove all valves and place in order,
head) after refacing (fig. 6-24) must be re-
and tag so that both intake and exhaust valve
placed. Compare refaced valve with new valve
do not become mixed in handling,
to check margin thickness. Check all refaced
(3) Lift out and separate cap (5), screw
or new valves in 5 blocks with indicator (fig.
(6) and tappet (7).
(4) Remove inserts (8) and guides (9)
stem within 0.002 inch. If not, repeat refacing
only if in need of replacement.
