S&S Cycle Piston and Cylinder Kits for all 1986-up Harley-Davidson Sportster Models - Manual (Page 2)

1. Remove the cylinder heads, cylinders, and pistons according to
the procedures in the Harley-Davidson® service manual.
2. For 2004-up models – prior to installing the new S&S pistons
and cylinders, move tappet covers as far as possible to toward
the outside of the engine (away from the cylinders) to ensure
adequate clearance between the tappet covers and cylinder
bases.
a. Remove tappet covers from crankcase
b. Clean tappet covers, reusable gaskets, crankcase gasket
surface, and hardware with solvent and a clean rag.
c. Apply blue thread locking compound to tappet cover screws.
d. Reinstall tappet cover gaskets, covers, and screws, but do not
final tighten.
e. Hold the tappet cover as far away from the cylinders as
possible. See Picture 1, below.
f. Torque screws to 120 In*lb in a criss-cross pattern.
3. Install S&S Pistons
NOTES:
• These S&S piston scan be used in either the front or rear position.
However, when purchased in a kit with cylinders, each piston must be
kept with the cylinder it was delivered in, as each cylinder is individually
honed to fit a specific piston.
• Rebalancing is not required when installing this kit.
a. Clean pistons and wrist pins with solvent.
NOTE: Wristpin must be thoroughly cleaned before installation, paying
particular attention to bore. Pass clean, lint-free cloth back and forth
through wristpin bore several times to insure removal of all contaminants.
b. Apply assembly lube to connecting rod bushings, wristpins,
and piston wristpin holes.
c. Install pistons with the FWD arrow mark pointing toward the
front of the engine. See Picture 2, below, left.
d. Ensure that wristpin clip groove in piston is free of burrs
and foreign matter. Install wire clips using procedure
recommended in a Harley-Davidson® service manual. End
of clip must rest over notch in piston below wristpin hole to
allow removal of clip in future. Be sure clip is fully seated in
groove.
NOTE: Round “wire” style clips supplied with this kit are identical to and
interchangeable with stock clips in Harley-Davidson® Evolution® engines.
4. Install Piston Rings
NOTE: Ring widths on some piston series may change from time to time.
Part numbers of rings originally supplied with pistons should be recorded
for future reference in the event replacement rings are required.
a. Measure ring end gap by pushing ring about 1 inch into the
cylinder bore from the head end of the cylinder, using the
piston to insert the ring squarely in the bore. See Picture 3,
below. Measure the gap between the ends of the ring with
a feeler gauge. See Picture 4, next page. Compression ring
end gap should be between .016" to .026". Oil ring rail end
gap should be between .010 to .050". If there is insufficient
ring end gap, file the end of the piston ring to achieve the
desired gap. Ends of piston ring must be deburred after filing.
b. Thoroughly clean the piston rings after filing and deburring
and install on pistons.
2
Picture 3
Picture 1
Suggested ring end gaps
Ring
Ring Gap Tolerance (inches)
Target Gap
Min Max
Top 0.016 0.022 0.017
2nd 0.016 0.026 0.021
Oil ring rails 0.010 0.050 0.010 to 0.050
Picture 2