Yamaha XG250, Service Manual

Page: 155 / 278

ROCKER ARM, CAMSHAFT
5-13
EAS23770
REMOVING THE ROCKER ARMS AND
CAMSHAFT
1. Loosen:
●
Locknuts “1”
●
Valve clearance adjusting screws “2”
●
Stopper plate “3”
2. Remove:
●
Camshaft “1”
●
Bearing; “2”
NOTE:
Screw 10 mm (0.396 in) bolt “3” into the thread-
ed end of the camshaft and then pull out the
camshaft.
3. Remove:
●
Intake rocker arm shaft
●
Exhaust rocker arm shaft
●
Intake rocker arm
●
Exhaust rocker arm
NOTE:
Remove the rocker arm shafts with the slide
hammer “1” and weight “2”.
EAS23840
CHECKING THE CAMSHAFT
1. Check:
●
Bearing
Damage/wear
→
Replace.
2. Check:
●
Camshaft lobes
Blue discoloration/pitting/scratches
→
Re-
place the camshaft.
3. Measure:
●
Camshaft lobe dimensions “a” and “b”
Out of specification
→
Replace the camshaft.
Slide hammer bolt
90890-01083
Slide hammer bolt 6 mm
YU-01083-1
Weight
90890-01084
YU-01083-3
1
2
3
1
2
3
Camshaft lobe dimension limit
Intake A
36.520
–
36.620 mm (1.4378
–
1.4417
in)
Limit
36.460 mm (1.4354 in)
Intake B
30.201
–
30.301 mm (1.1890
–
1.1930
in)
Limit
30.151 mm (1.1870 in)
Exhaust A
36.564 – 36.664 mm (1.4395 – 1.4435
in)
Limit
36.514 mm (1.4376 in)
Exhaust B
30.216
–
30.316 mm (1.1896
–
1.1935
in)
Limit
30.166 mm (1.1876 in)
1
2