S&S Cycle Big Twin Engines with 3-1/2 and 3-5/8 Bore Crankcases and Special Application (SA) 4 Bore Crankcases - Manual (Page 15)

NOTE - In new installation, hydraulic lifters can take extremely
long periods of time to “pump up.” Motorcycle should be ridden
during this time and prolonged idling avoided. Brisk acceleration
may help stubborn lifter to pump up. If noise persists, consider
the following:
A. Improper lifter/pushrod adjustment in customer-
assembled engine. See HL
2
T Kit Instructions #51-1039
and Pushrod instructions #51-1035.
B. Silicone or other foreign matter obstructing applications
crankcase oil screen assembly. Refer to crankcase
instructions page 3, section 3-B. Remove, inspect, and
clean screen as necessary.
C. Low oil pressure - Refer to number 5 above and Service
Bulletin 15 in Oil Pump Instructions.
6. Excessive crankcase pressure as evidenced by multiple
oil leaks or filler cap blowing out of oil tank when
engine started.
A. Oil lines kinked or installed incorrectly. Check oil return
line and crankcase vent hose.
B. ‘91-earlier lower rocker cover gaskets used in engine
that vents out cylinder heads only. Early gasket will
pressurize oil tank via vent line, causing cap to blow out.
7. Engine expels excessive oil through crankcase breather
A. Oil lines installed incorrectly. Connecting primary
housing scavenge fitting to tee in oil tank vent line can
drain contents of oil tank into crankcase. Scavenge
fitting should be removed from engine having open or
sealed primary, and hole plugged. Oil will also drain into
crankcase if feed line from tank connected to return
fitting on pump.
B. If gear cover has been removed, check to see that
correct gasket was used for reinstallation. Gear cover
gasket must be ‘92-older style if crankcase venting used.
C. If S&S ® gear cover replaced with other brand, check
closely for manufacturing defects and confirm that new
cover is compatible with crankcase venting. (See
Vent/Breather System comments on page 7.)
D. Chain oiler adjustment screw replaced with standard
machine screw in Model 6250 oil pump. 6250 pump is
seldom used on engines except with certain generator
crankcases. 6250 pump can be identified by chain oiler
adjustment screw on side of pump body.
8. Exhaust smoke
A. Restricted oil return line.
B. Carburetor overly rich or enrichener used excessively.
C. Excessive lubrication applied to cylinder wall/piston
rings during assembly.
D. Piston rings installed incorrectly or damaged
during installation.
9. Overheating
NOTE - Oil temperature up to approximately 220˚F is normal.
Prolonged temperature of 240˚F or greater is excessive and
should be investigated. Consider following possible causes.
A. Retarded ignition timing.
B. Carburetor jetting too lean.
C. Intake manifold/carburetor air leak. If VOES not used,
hose fitting in manifold must be plugged.
D. Spark plug heat range too hot.
E. Restricted oil supply.
F. Insufficient air flow from running engine too long at
stop or in slow-moving traffic.
10. Vibration
NOTE - Vibration can have many causes outside engine.
Following should be ruled out before suspecting engine.
A. Tires/wheels out of balance or not round.
B. Engine or transmission not square in frame.
C. Motor mount loose, or worn rubber mount.
D. Drive sprockets worn or out of alignment.
E. Drive belt/chain worn or out of adjustment.
F. Rear cylinder ignition timing different than front (for
ignition with independent timing adjustment for front
and rear cylinders).
G. Ignition module malfunction.
H. Contaminated or poor quality gasoline.
NOTE - S&S has found that vibration caused by poor quality
gasoline can in some instances be reduced or eliminated by using
spark plugs one heat range colder than normally recommended.
I. Frame bent or broken.
J. Exhaust system or other heavy component mounted
incorrectly or inadequately supported. Check for loose
or broken support bracket.
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