Operating instructions

4-19
4-23. OIL PUMP ASSEMBLY (See Figure 4-18).
a. Loosen oil screen (6) and tachometer drive housing
(12) to facilitate later removal. (Tachometer drive
housing has a left hand thread.) Remove ten sets of
attaching parts (1, 2, 3) and pull pump assembly to the
rear. Remove gasket (5).
b. Remove oil screen (6) and gasket (7).
c. Remove attaching parts (8,9,10) and separate cover
(11) from pump housing (4). Remove tachometer
drive housing (12). Press oil seal (15) from housing.
Remove gasket (13) and tachometer drive shaft (14).
d. Remove oil pump drive gear assembly and separate
tachometer drive gear (33) oil pump drive gear (34)
and pin (35). Remove oil pump driven gear and
bushing assembly (36, 37).
e. Remove oil pressure relief valve (38 through 43).
Remove by-pass assembly (46 through 48).
4-24. OIL PUMP ASSEMBLY, FULL FLOW (See
Figure 4-19).
a. Cut lockwire and remove filter (1). Remove
attaching parts (2,3,4) and separate adapter (5) and
gasket (6) from oil pump housing (10).
b. If electric tachometer (33 through 37) is used,
loosen tachometer housing (36) at this time. (Housing
has a left-hand thread.)
c. Remove attaching parts (12, 13, 14) and lift off
housing (15). Remove attaching parts (16,17, (18)
and (21,22,23) and remove covers (19) and (24).
Remove gaskets (20) and (25).
d. Remove oil seal (26) and shaftgear (27).
e. If electric tachometer is used, remove attaching
parts (30,31,32) and separate cover (33) from oil
pump housing (10). Remove tachometer drive
housing (36), oil seal (35) and shaftgear (34).
f. Remove attaching parts (7,8,9) and pull oil pump
assembly from crankcase studs. Remove gasket (11).
g. Lift out shaftgear assembly (38 through 40) and
driven gear assembly (41, 42).
h. Remove oil pressure relief valve (43 through 50)
from oil pump housing.
i. Parts (51 through 65) have been replaced by a new
style spin on filter.
4-25. CYLINDERS AND PISTONS (See Figure
4-20).
a. Rotate engine stand so engine is in inverted
position. Remove attaching parts (1, 2, 3), cover (4)
and gasket (5).
b. Position crankshaft so valve lifters of cylinder to be
removed are on heels of cam lobes and both valves are
fully closed. Remove screw (6), washer (7), shafts
(8), rocker assemblies (9, 10, 11) and thrust washers
(12). Withdraw pushrods (13). Repeat these steps on
remaining cylinders.
c. Push the pushrod housing (14) against the spring
(15) until the cylinder flange end is clear. Lift
cylinder end of housing and withdraw from crankcase.
Remove spring (15), washers (16) and packing (17).
d. Remove two sets of attaching parts (18, 19) from
each cylinder flange. Rotate engine stand so engine is
in upright position. Make certain piston in cylinder to
be removed is top dead center. Remove nuts (19).
Cradle cylinder in arm and withdraw it straight
outward. Catch piston with other hand as it clears the
cylinder to prevent damage to piston or crankcase.
e. Remove piston pin (20) and piston (21) with rings
(22,23,24,25) as an assembly.
f. Remove packing (26). Use of a cylindrical wood
block anchored to a work bench, with provisions for
clamping the cylinder in place, is recommended to
facilitate removal of valve springs and to prevent
dropping of valves.
g. Compress valve springs and remove keys (27). Be
careful not to cock retainers (28, 29) and score valve
stems. Remove rotocoil (28) or outer retainer (29),
outer spring (30), inner spring (31) and inner retainer
(32). Hold valve stems while lifting cylinder from its
support, and lay cylinder on its side. Stone down any
nicks before removing valve stems (33, 34). It is
recommended that all exhaust valves be replaced at
each major overhaul regardless of condition.
h. Remove rings (22,23,24 and 25) from piston (21).
Be careful not to score ring lands with ring ends.