Caution – S&S Cycle Bore Stroker Kit 3 3/16 for Harley-Davidson Sportster Models User Manual

Page 11

Gearing Note

●

Gearing depends on total weight of machine and rider/s,
size of engine, caming, exhaust system and type of riding
to be done. Most strokers are capable of pulling more
gear. We suggest you break engine in with stock gearing
to minimize lugging engine. After engine is broken in you
will have a better feel of its potential and can change
gearing accordingly.

●

For those who wish to determine their final drive gear ratio
the formula is as follows:

Break-In Procedure

NOTE - These engines must be broken in. They will feel extremely
strong, but resist the impulse to turn it on. Break it in properly.

Lugging or running engine prematurely at high rpms may
result in damage to pistons and/or other engine components.
S&S

voids its guarantee if engine is not broken in properly.

Break engine in using following procedure:

On initial engine startup, don’t just sit and idle motor
while you admire your work, or tinker with minor
adjustments. Heat buildup can be excessive.

First 50 miles are most critical for new rings and piston
break-in. Most engine damage will initially occur during
this period. Keep heat down by not exceeding 2500
rpm. Vary speed. Do not lug engine.

Next 500 miles should be spent running engine no faster
than 3500 rpm or about 50-55 mph. Do not lug engine
and continue to vary speed.

For balance of first 1000 miles, speed can be run up to
60 to 70. Continue to run engine at all different speeds
including lower 40-45 mph ranges.

1000 to 2000 miles—basically same procedures as
before. You can be a little more liberal with rpm range.
Avoid overheating engine and putting any hard strain
on it (drag racing, trailer towing, sidecar operation).

2000 miles and up—have fun!

CAUTION