Yamaha XG250, Service Manual

Page: 55 / 278

ENGINE
3-4
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
4. Adjust:
●
Valve clearance
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Loosen the locknut “1”.
b. Insert a thickness gauge between the end of
the adjusting screw and the valve stem.
c. Turn the adjusting screw “2” until the speci-
fied valve clearance is obtained.
●
Hold the adjusting screw to prevent it from
moving and tighten the locknut to specifica-
tion.
d. Measure the valve clearance again.
e. If the valve clearance is still out of specifica-
tion, repeat all of the valve clearance adjust-
ment steps until the specified clearance is
obtained.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
5. Install:
●
O-rings
●
Cylinder head side cover 1
●
O-rings
●
Cylinder head side cover 2
●
O-rings
●
Cylinder head side cover 3
●
Spark plug
●
Spark plug caps
6. Install:
●
Fuel tank
●
Fuel tank side cover (left and right)
●
Seat/side cover (left and right)
Refer to “GENERAL CHASSIS” on page 4-1.
EAS20580
CHECKING THE EXHAUST GAS
(When the air induction system is not operat-
ing)
1. Stand the vehicle on a level surface.
NOTE:
●
Place the vehicle on a suitable stand.
●
Make sure the vehicle is upright.
●
Measure the exhaust gas at idle when the air
induction system is not operating.
2. Install:
●
Temperature probe tester “1”
(onto the engine oil drain bolt)
●
Digital tachometer
●
Exhaust attachment
(onto the exhaust pipe)
Thickness gauge
90890-03079
Narrow gauge set
YM-34483
Tappet adjusting tool
90890-01311
Valve adjuster 3 mm & 4 mm
YM-08035-A
Locknut
14 Nm (1.4 m•kg, 10 ft•lb)
2
1
T
R
.
.
New
New
Cylinder head side cover
18 Nm (1.8 m•kg, 13 ft•lb)
Cylinder head side cover bolts
10 Nm (1.0 m•kg, 7.2 ft•lb)
Spark plug
18 Nm (1.8 m•kg, 13 ft•lb)
Pocket tester
90890-03132
Digital tachometer
90890-06760
T
R
.
.
New
T
R
.
.
T
R
.
.