Piston Ring - Yamaha XT550J Service Manual

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Size A
Standard 92.00 mm (3.622 in)
Oversize 1 92.25 mm (3.632 in)
Oversize 2 92.50 mm (3.642 in)
Oversize 3
92.75mm (3.652 in)
Oversize 4 93.00mm (3.662 in)
2. Piston ring/ring groove fit must have
correct clearance. If the piston and ring
have already been used in the engine,
the ring must be removed, the ring
groove cleaned of carbon, then the ring
should be reinstalled. Use a feeler gauge
to measure the gap between the ring
and the land.
Top
0.04 - 0.08 mm
(0.0016 - 0.0031 in)
Side clearance 2nd
0.03 - 0.07 mm
(0.0012 - 0.0028 in)
Oil ring
0.02 - 0.06 mm
(0.0008 - 0.0024 in)
Piston ring
The oversize top and middle ring sizes are
stamped on top of the ring.
Oversize 1 0.25mm (0.0098 in)
Oversize 2 0.50 mm (0.0197 in)
Oversize 3 0.75mm (0.0295 in)
Oversize 4 1.00 mm (0.0394 in)
The expander spacer of the bottom ring (oil
control ring) is color-coded to identify sizes.
The color mark is painted on the expander
spacer.
3-20
Size Color
Oversize 1
Brown
Oversize 2
Blue
Oversize 3 Black
Oversize 4
Yellow
1. Measure the end gap of each piston
ring. Insert a ring into the cylinder, and
push it approximately 20 mm (0.8 in) in-
to the cylinder. Push the ring with the
piston crown so the ring will be at a right
angle to the cylinder bore.
2. Measure the ring end gap with a feeler
gauge. If the end gap exceeds
tolerance, replace the whole set of rings.
NOTE: _ _ _ _ _ _ _ _ _ _ _ _
You cannot measure the end gap on the ex-
pander spacer of the oil control ring. If the oil-
control-ring rails show excessive gap, replace
all three rings.
~
Standard Limit
Top ring
0.2-0Amm
0.80mm
(0.0079 - 0.0157 in) (0.0315 in)
2nd ring
0.2-0.4mm
0.80mm
(0.0079 - 0.0157 in)
(0.0315in)
Oil ring
O.3-0.9mm
-
(Rails)
(0.0118 - 0.0354 in)