Yamaha XT660X Service Manual

5 - 24
ENG
VALVES AND VALVE SPRINGS
EAS00237
REMOVING THE VALVES
The following procedure applies to all of the
valves and related components.
NOTE:
_
Before removing the internal parts of the cylin-
der head (e.g., valves, valve springs, valve
seats), make sure the valves properly seal.
1. Check:
• valve sealing
Leakage at the valve seat
→
Check the
valve face, valve seat, and valve seat width.
Refer to “CHECKING THE VALVE SEATS”.
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a. Pour a clean solvent
a
into the intake and
exhaust ports.
b. Check that the valves properly seal.
NOTE:
_
There should be no leakage at the valve seat
1
.
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2. Remove:
• valve cotters
NOTE:
_
Remove the valve cotters by compressing the
valve spring with the valve spring compressor
1
and the valve spring compressor attach-
ment
2
.
Valve spring compressor
90890-04019
Valve spring compressor attach-
ment
90890-01243

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