Yamaha XT660X Service Manual

5 - 36
ENG
CYLINDER AND PISTON
EAS00263
CHECKING THE PISTON RINGS
1. Measure:
• piston ring side clearance
Out of specification
→
Replace the piston
and piston rings as a set.
NOTE:
_
Before measuring the piston ring side clear-
ance, eliminate any carbon deposits from the
piston ring grooves and piston rings.
2. Install:
• piston ring
(into the cylinder)
NOTE:
_
Level the piston ring into the cylinder with the
piston crown.
a
40 mm (1.57 in)
3. Measure:
• piston ring end gap
Out of specification
→
Replace the piston
ring.
NOTE:
_
The oil ring expander spacer’s end gap cannot
be measured. If the oil ring rail’s gap is exces-
sive, replace all three piston rings.
Piston ring side clearance
Top ring
0.030 ~ 0.080 mm
(0.0012 ~ 0.0031 in)
<Limit>: 0.13 mm (0.0051 in)
2nd ring
0.030 ~ 0.070 mm
(0.0012 ~ 0.0028 in)
<Limit>: 0.11 mm (0.0043 in)
Piston ring end gap
Top ring
0.20 ~ 0.35 mm
(0.0079 ~ 0.0138 in)
<Limit>: 0.60 mm (0.0236 in)
2nd ring
0.35 ~ 0.50 mm
(0.0138 ~ 0.0197 in)
<Limit>: 0.85 mm (0.0335 in)
Oil ring
0.20 ~ 0.70 mm
(0.0079 ~ 0.0276 in)

Yamaha XT660X Specifications

General

Displacement	660cc
Bore x Stroke	100.0 mm x 84.0 mm
Compression Ratio	10.0:1
Fuel System	Fuel Injection
Ignition System	TCI
Transmission	5-speed
Final Drive	Chain
Rear Brake	Single disc, Ø 245 mm
Front Tyre	120/70 R17
Rear Tyre	160/60 R17
Maximum Power	48 HP (35.3 kW) @ 6, 000 rpm
Maximum Torque	58.4Nm (43.1lb-ft) @ 5, 250rpm
Front Suspension	Telescopic fork
Rear Suspension	Swingarm, (link suspension)
Fuel Tank Capacity	15 litres
Engine Type	Liquid-cooled, 4-stroke, single cylinder, SOHC, 4-valves