Yamaha YZF-R1 1998, Service Manual, Page: 204 / 418

4 - 68
ENG
CONNECTING RODS AND PISTONS
3. Measure:
• piston ring end gap
Out of specification
→
Replace the pis-
ton ring.
NOTE:
The oil ring expander spacer’s end gap
cannot be measured. If the oil ring rail’s
gap is excessive, replace all three piston
rings.
Piston ring end gap
Top ring
0.19 ~ 0.31 mm
<Limit>: 0.56 mm
2nd ring
0.30 ~ 0.45 mm
<Limit>: 0.80 mm
Oil ring
0.10 ~ 0.35 mm
EB404421
CHECKING THE PISTON PINS
The following procedure applies to all of
the piston pins.
1. Check:
• piston pin
Blue discoloration/grooves
→
Replace
the piston pin and then check the lubri-
cation system.
2. Measure:
• piston pin outside diameter
a
Out of specification
→
Replace the pis-
ton pin.
Piston pin outside diameter
16.991 ~ 17.000 mm
<Limit>: 16.971 mm
3. Measure:
• piston pin bore diameter (in the piston)
Out of specification
→
Replace the pis-
ton pin.
Piston pin bore diameter
(in the piston)
17.002 ~ 17.013 mm
<Limit>: 17.043 mm