buell s1 lightning '97 Manual
3-23
NOTE
Since the piston pin is a loose fit in the piston, the pin will eas-
ily slide out. The pins have tapered ends to help seat the
round retaining rings. See
ily slide out. The pins have tapered ends to help seat the
round retaining rings. See
1200cc piston pins
are stamped with a V-groove at one end.
9.
Mark each pin boss with either an “F” or an “R” to indi-
cate front or rear cylinder, respectively. See
cate front or rear cylinder, respectively. See
The arrow at the top of 1200cc pistons must always point
toward the front of the engine.
toward the front of the engine.
1
CAUTION
Handle the piston with extreme care. The alloy used in
these pistons is very hard. Any scratches, gouges or
other marks in the piston could score the cylinder during
engine operation and cause engine damage.
these pistons is very hard. Any scratches, gouges or
other marks in the piston could score the cylinder during
engine operation and cause engine damage.
10. Spread piston rings (6) outward until they clear grooves
in piston (3) and lift off.
CLEANING, INSPECTION
AND REPAIR
AND REPAIR
1.
Soak cylinder and piston in an aluminum-compatible
cleaner/solvent until deposits are soft, then clean with a
brush. Blow off loosened carbon and dirt particles and
wash in solvent.
cleaner/solvent until deposits are soft, then clean with a
brush. Blow off loosened carbon and dirt particles and
wash in solvent.
2.
Clean oil passage in cylinder with compressed air.
3.
Clean piston ring grooves with a piece of compression
ring ground to a chisel shape.
ring ground to a chisel shape.
4.
Examine piston pin to see that it is not pitted or scored.
5.
Check piston pin bushing to see that it is not loose in
connecting rod, grooved, pitted or scored. A piston pin
properly fitted to upper connecting rod bushing has a
0.00125 to 0.00175 in. (0.0317-0.0444 mm) clearance in
bushing. If piston pin-to-bushing clearance exceeds
0.00200 in. (0.0508 mm), replace worn parts. See
connecting rod, grooved, pitted or scored. A piston pin
properly fitted to upper connecting rod bushing has a
0.00125 to 0.00175 in. (0.0317-0.0444 mm) clearance in
bushing. If piston pin-to-bushing clearance exceeds
0.00200 in. (0.0508 mm), replace worn parts. See
.
6.
Clean piston pin retaining ring grooves.
7.
Examine piston and cylinder for cracks, burnt spots,
grooves and gouges.
grooves and gouges.
8.
Check connecting rod for up and down play in lower
bearings. When up and down play is detected, lower
bearing should be refitted. This requires removing and
disassembling engine crankcase.
bearings. When up and down play is detected, lower
bearing should be refitted. This requires removing and
disassembling engine crankcase.
Checking Gasket Surface
1
CAUTION
If either cylinder gasket surface does not meet flatness
specifications, replace cylinder and piston. Proper toler-
ances will extend component life and prevent leaks.
specifications, replace cylinder and piston. Proper toler-
ances will extend component life and prevent leaks.
1.
See
Check that cylinder top (head) gasket
surface is flat within 0.006 in. (0.15 mm). Lay a straight
edge across the surface, then try to insert a feeler gauge
between the straightedge and the gasket surface.
edge across the surface, then try to insert a feeler gauge
between the straightedge and the gasket surface.
2.
Check that the cylinder base gasket surface is flat within
0.008 in. (0.20 mm). Lay a straightedge across the sur-
face, then try to insert a feeler gauge between the
straightedge and the gasket surface.
0.008 in. (0.20 mm). Lay a straightedge across the sur-
face, then try to insert a feeler gauge between the
straightedge and the gasket surface.
Figure 3-28. Piston Pin and Piston Identification
b0057a3x
V-groove