Caution – S&S Cycle Stroker Kits 106 for Harley-Davidson Twin Cam 88 Engines User Manual

Page 7

Clean oil tank and oil cooler, if applicable, and flush or
replace oil lines before installing engine in frame.

If engine is run with foreign material in the oil tank, engine
damage will occur. Engine damage caused by foreign material
in the oil tank is not covered under the S&S

warranty.

4. Engine break-in procedure.

NOTE - S&S engines are designed for high performance and as
such are not tolerant of inadequate break-in. Correct break-in
will assure longer engine life and will prevent unnecessary
engine damage. Engine damage caused by improper break-in is
not covered under the S&S warranty.

A. Initial start up. Run engine approximately one minute at

1250-1750 rpm. DO NOT crack throttle or subject to any
loads during this period as head gaskets are susceptible
to failure at this time. During this time, check to see that
oil pressure is normal, that oil is returning the oil tank,
and that no leaks exist.

B. Shut off engine and thoroughly check for any leaks or

other problems. Let engine cool to the touch.

C. After engine has cooled, start up again and allow the

motor to build some heat. Engine should be run no
longer than three to four minutes. When the cylinders
become warm/hot to the touch (approximately 150°)
shut the motor down and let it cool to room temp.
Follow the same cautions as for the initial start-up, and
continue to watch for problems.

D. Repeat this procedure 3 or 4 times. Each successive time

it should take slightly longer to warm up and you can
increase the temp slightly each time (+10°). You can be
more liberal each time with the rpm, gently vary rpm
continuously from idle up to 2500 rpm in the final cycle.
Don’t be too concerned with final carb settings at this
time because idle speed and mixture cannot be correctly
set until the motor reaches full operating temperature.
The motor should not reach that temperature during
these cycles. Do not allow engine temperature to
become excessive. After the motor has cooled to room
temperature for the final time you are ready to start the
1000 mile engine break-in process.

E. The first 50 miles are most critical for new rings and

piston break-in. Engine damage is most likely to occur
during this period. Keep heat down by not exceeding
2500 rpm. Avoid lugging the motor, riding in hot
weather or in traffic. Vary the engine speed. Do not lug
the engine. We recommend changing the oil at 50 miles.

The next 500 miles should be spent running engine
no faster than 3500 rpm or 60 mph. Avoid continuous
steady speeds, and do not lug the engine. Vary
engine rpm. We recommend changing the oil again
at 500 miles.

Lugging or running engine prematurely at sustained high rpm
may result in damage to pistons and other engine components.
S&S voids its guarantee if engine is not broken in properly.

G. For the balance of the first 1000 miles the motor can be

run in a normal but conservative manner. You can be
more liberal with the rpm range and motorcycle can be
operated at normal highway speeds. Avoid overheating
or putting any hard strain on the engine: no drag
racing, dyno runs, excessive speed, trailer towing or
sidecar operation.

H. After 1000 miles, verify carburetor jetting and

adjustment. Change the engine oil. Motorcycle can now
be operated normally.

I. Have

Fun!

Performance Notes:
●

Ignition system - S&S engine kits for Harley-Davidson

Twin

Cam 88

, we recommend that an aftermarket or high

performance ignition module be used. Engines built with
S&S kits have higher than stock compression ratios,
performance cams, and in some cases cylinder heads with
combustion characteristics that are different from stock.
These and other factors effect the ignition requirements of
the engine. Programmable ignition systems allow ignition
maps to be optimized for a specific application, but should
be programmed by a qualified technician. Consult the
ignition manufacturer for recommendations regarding use
of a specific ignition system with large displacement high
compression engines.

●

Spark plugs - Use spark plugs and wires that are compatible
with the ignition system. Dual plug installations in S&S Super
Stock

heads are not generally necessary.

●

All S&S test engines are run using S&S carburetors. S&S Super
E and G carburetors are recommended for most applications
with the Super G being used more often on larger
displacement, freer breathing engines with higher
compression ratios. Typically, engines equipped with S&S
heads require the same or slightly leaner jetting than those
engines fitted with stock heads. Consult the carburetor
jetting instructions for specific jetting recommendations.

●

If another type carburetor is used, it must be made to run
rich enough to operate properly and to prevent engine
damage. If you have a problem with another carburetor, S&S
cannot help you and recommends you call the carb
manufacturer with any questions you may have.

●

If the motorcycle is used exclusively on a drag strip where
engine temperatures vary, slightly richer jets may be
necessary for best performance. Larger jets/richer mixtures
will enable one to run a colder engine which is sometimes
desirable. This is best determined by experimentation.

CAUTION