Yamaha XV19SX(C), Service Manual

Page: 276 / 494

CAMSHAFTS
5-27
5. Measure:
• Crankcase hole inside diameter “a”
Out of specification
→
Replace the crank-
case.
6. Measure:
• Camshaft cover hole inside diameter “a”
Out of specification
→
Replace the camshaft
cover.
7. Calculate:
• Camshaft-to-crankcase clearance
Out of specification
→
Replace the defective
part(s).
NOTE:
Calculate the clearance by subtracting the cam-
shaft journal diameter (crankcase side) from the
crankcase hole inside diameter.
8. Calculate:
• Camshaft to camshaft cover clearance
Out of specification
→
Replace the defective
part(s).
NOTE:
Calculate the clearance by subtracting the cam-
shaft journal diameter (camshaft cover side)
from the camshaft cover hole inside diameter.
9. Check:
• Camshaft drive gears
• Camshaft driven gears
• Front cylinder camshaft gears
• Rear cylinder camshaft gears
Chips/pitting/roughness/wear
→
Replace the
defective part(s).
EAS23890
CHECKING THE ROCKER ARMS AND
ROCKER ARM SHAFTS
The following procedure applies to all of the
rocker arms and rocker arm shafts.
1. Check:
• Rocker arm
Damage/wear
→
Replace.
2. Check:
• Rocker arm shaft
Blue discoloration/excessive wear/pitting/
scratches
→
Replace or check the lubrication
system.
3. Measure:
• Rocker arm inside diameter “a”
Out of specification
→
Replace.
Crankcase hole inside diameter
25.000–25.021 mm (0.9843–
0.9851 in)
Camshaft cover hole inside diam-
eter
28.000–28.021 mm (1.1024–
1.1032 in)
a
a
a a
a a
Camshaft to crankcase clearance
0.020–0.064 mm (0.0008–0.0025
in)
Camshaft to camshaft cover
clearance
0.020–0.064 mm (0.0008–0.0025
in)
Rocker arm inside diameter
18.000–18.018 mm (0.7087–
0.7094 in)