S&S Cycle Bore Stroker Kit 3 3/16 for Harley-Davidson Sportster Models - Manual (Page 10)

Final Assembly
A. Install and tighten cylinders, cylinder heads and
manifold as in standard assembly.
NOTE - Retighten cylinder base nuts and head bolts as necessary
after engine has been run.
B. Install engine in frame.
C. Install engine head mount.
NOTE - Stock head mount will be short if you are installing S&S ®
stroker kit with cylinder base plates. If 1 ⁄
16
” thick or less plates are
used, modify stock mount. If plates thicker than 1 ⁄
16
” are used,
install S&S extra long head mount.
12. Timing, Carburetion, Exhaust, Gearing and Break-in (All)
Ignition Timing Notes
●
See Step 5, “Lower End Assembly”, for explanation of S&S
timing marks.
● S&S flywheels have timing marks that position pistons at 40°
before top center, same as stock, when mark is in center of
timing hole. Placing mark to right side of hole or just
entering hole advances timing almost 5°. Vice versa, if mark
is just leaving hole, timing is retarded almost 5°.
● Set ignition timing on all engines at 40°. On engines
equipped with vacuum operated advance mechanism, set
timing using Factory procedures.
● Ignition timing for engines with dual plugged heads should
generally be retarded 5-8° from the stock setting. However,
due to the large number of factors involved, optimum
ignition timing is impossible to accurately predict and must
be determined for each engine by experimentation.
Improper ignition timing may cause excessive engine heat
which may damage pistons and/or other engine components.
Carburetion Notes
● All S&S test engines have been run with S&S carburetors. A
Super E or Super G carburetor is recommended for most
strokers. Consult carburetor jetting instructions for specific
jetting recommendations.
● If another type carburetor is used, it must be made to run
rich enough so engine is not damaged. Other carburetor
types are a personal problem and we cannot answer
questions concerning them. It is best to call carb
manufacturer if you have any questions.
Exhaust Systems Notes
● To establish performance guidelines, S&S used 30” long stock
diameter drag pipes with good results. We suggest you try
them on these engines to establish a baseline to compare
with other systems.
● You might ask the manufacturer of the exhaust system you
are considering if he has had any experience with S&S
strokers. Many systems are made for looks with little
consideration given to performance. Most stock systems and
many aftermarket ones tried are too restrictive for good
performance. S&S does offer a series of slip-on mufflers that
can be used with stock header pipes. These work very well
in most situations and offer an inexpensive alternative to a
new exhaust system.
10
CAUTION