Generac Power Systems 941-2 - Manual (Page 84)

Section 5.1
ENGINE OIL SYSTEM
OIL PUMP (CONTINUED)
INSPECTION (CONT'D):
Inspect the outer drive pins on the camshaft. Look for
breakage, bending, other damage. These are roll pins
which can be removed and replaced.
Figure 3. Oil Pump Check Points
CRANKSHAFT OIL SEALS
An oil seal is provided in the crankcase and in the oil
sump, to prevent leakage past the crankshaft jour-
nals. See Figure 4.
A defective or leaking seal can be replaced. If the
crankshaft has been removed from the engine, old
seals can be removed by tapping out with a screw-
driver or punching them out from inside. Oil seal
pullers are available commercially, for seal removal
with the crankshaft installed.
Always use a seal protector when installing the crank-
shaft into its crankcase bore and when installing the
oil sump over the crankshaft.
Figure 4. Crankshaft Oil Seals
PRESSURE RELIEF VALVE
DESCRIPTION:
A ball type pressure relief valve is located in a bore of
the crankcase. The ball and spring are retained in the
crankcase bore by a spring retainer.
The Relief Valve serves to limit oil pressure to a maxi-
mum value. The ball will remain against its seat as
long as oil pressure in the crankcase ail passage is
below approximately 30 psi (29 kg/cm ). Should oil
pressure increase above that value, the ball will be
forced off its seat to relieve excess pressure into the
crankcase.
Figure 5. Oil Pressure Relief Valve
INSPECTION:
Remove the 8mm screw that retains the spring
RETAINER to the crankcase interior. Remove the
RETAINER, SPRING and BALL. Clean all parts in
solvent.
Inspect the BALL and RETAINER for damage, exces-
sive wear. Replace any damaged or worn compo-
nents. Inspect the SPRING and replace if damaged
or worn.
Apply a known test load to the SPRING, sufficient to
compress the spring to a length of 1.03 inch
(26.3mm). The amount of the test load at the stated
spring length should be as follows:
FORCE REQUIRED TO COMPRESS
RELIEF VALVE SPRING TO 1.03 INCH (26.3mm)
0.86-0.95 pounds (0.43-0.39 kg)
If the test load at the stated length is not within limits,
replace the SPRING.
BREATHER ASSEMBLY
DESCRIPTION:
A crankcase breather is located in the crankcase
assembly.
1
2
3
4
1. SCREW
2. RETAINER
3. SPRING
4. BALL
Page 5.1-2