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 14)

TECHNICAL SUPPORT
S&S ® Cycle strives to manufacture quality products well suited for
their intended use. In most cases, problems with completed
engines are caused by parts or circumstances beyond S&S’s
control. The following section will be helpful in dealing with
many such problems. In the event additional technical support is
required, please contact the S&S Technical Services Department
at 608-627-TECH (8324), FAX 608-627-0766, or E-mail
[email protected].
TROUBLESHOOTING
1. Starter will not turn engine over.
NOTE - New engines are hard to turn over because of friction
between tightly fit parts. They will loosen considerably after
approximately 2000 miles. Most 1990-up gear reduction starters
in good condition will start S&S engines with little difficulty.
1984-1989 model starters are less powerful and may labor, but
should work for most applications if in good condition. Hitachi
®
and Prestolite ® shovelhead starters in good condition are
adequate for most shovelhead engines up to 98 cubic inches. 103
cubic inch may require heavy duty or modified stock starter.
Accel
® Motorcycle Products manufactures “high torque” field
coils that improve performance of Prestolite ® starters. The
following should also be considered when engine is difficult to
turn over.
A. Battery weak - Battery should be top of the line,
premium brand in new or like new condition with full
charge. S&S has had good results with Yuasa
® YuMicron-
CX and YTX20 series sealed batteries.
B. Worn or malfunctioning components in starter system:
starter motor, relay, solenoid, or drive.
C. Oil viscosity too heavy for climate.
D. Hydraulic lifters incorrectly adjusted.
E. Other brand pushrods substituted for S&S pushrods,
resulting in elevated cranking compression.
In situations where new engine is hard to turn over due to
friction and not other problem:
A. “Bump” starter button until compression stalls piston
near TDC. Turn off ignition switch for 10 seconds to
allow starter to cool and battery to recover.
B. If engine cold, prime carburetor with accelerator pump
and lift enrichener lever. Temperatures below 45˚F. may
require 3-5 additional “squirts” from accelerator pump
for engine to start quickly. Refer to carburetor
instructions for additional information.
C. Switch ignition on, engage starter and lower enrichener
lever as engine warms.
NOTE - Starting procedure can vary according to weather,
altitude, carb tuning, and ignition system. Regardless, engine
must be in good state of tune for reliable starting.
D. If engine remains difficult to start, check compression
with professional quality screw-in gauge as follows:
with gauge in place, remove other spark plug, hold
throttle wide open, and turn engine over rapidly with
starter. Reading below 185 PSI is normal. If reading
above 185 PSI, contact S&S Technical Services Dept.
2. Engine turns over but will not start
A. Compression low - Check pushrod adjustment.
B. No ignition - Confirm spark at spark plug. If weak or
absent, turn on lights to see if battery has good
charge. If lights dim, check wiring connections at
battery. If connections good, recharge or replace
battery. If lights bright but spark absent or weak, check
wiring connections at ignition switch, sensor, module,
and coil. If connections good but no spark, check for
open circuit breaker/blown fuse resulting from wiring
short. If none of above correct problem, troubleshoot
ignition system according to manufacturer’s
instructions and check timing.
C. No fuel - Refer to troubleshooting tips on pages 13-14 in
carburetor instructions.
3. Engine starts but runs poorly
A. Erratic fuel supply or poor carburetor tuning - Refer to
carburetor instructions. Pay particular attention to gas
tank venting. Audible hiss when cap loosened
indicates vent problem.
B. Ignition timing incorrect.
C. Loose wiring connection or faulty circuit breaker or
ignition switch.
D. Ignition malfunction. Check for faulty ignition
sensor, module, coil, condenser, intermittent
electrical short, etc.
F. Intake manifold air leak; refer to carburetor instructions.
G. Valves not seating due to incorrect pushrod adjustment.
H. Fouled spark plugs caused by overly rich carburetor
jetting, leaving enrichener on too long, or weak
ignition.
I. Contaminated or poor quality gasoline.
NOTE - Inferior or contaminated gasoline can cause hard starting,
power loss, and erratic performance. When poor quality gas is
suspected, several tankfuls of gasoline obtained from a source
known to be good should be run through the engine and then
used on a regular basis if improvement is noted. In some
instances, spark plugs one heat range colder than normal may
improve performance with marginal gasoline. Some gasoline
additives currently in use by petroleum companies cause hard
starting, power loss, and other problems blamed on the engine
or state of tune.
4. Low oil pressure
If air removed from pump before start-up, low oil pressure is
usually related to part other than engine or oil pump.
A. Check for worn bushings and excessive operating
clearances in old parts such as rocker assemblies or
gear cover.
B. If gear cover removed or replaced for any reason, check
that oil passage holes between gear cover, gasket, and
crankcase line up correctly. Gasket must not overlap
passage at all.
C. If non-S&S parts installed, closely examine them for
excessive running clearance or possible manufacturing
defect, especially porosity in pinion oil passage of gear
cover.
5. Noisy lifters
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