Checking The Push Rod Cover; Checking The Decompression System; Checking The Decompression Cam Spring - Yamaha XV19SX(C) Service Manual

Valve lifter outside diameter (in-
take)
22.962–22.974 mm (0.9040–
0.9045 in)
Valve lifter outside diameter (ex-
haust)
22.962–22.974 mm (0.9040–
0.9045 in)
4. Measure:
• Valve lifter case inside diameter "a"
Out of specification → Replace.
Valve lifter hole inside diameter
(intake)
23.000–23.021 mm (0.9055–
0.9063 in)
Valve lifter hole inside diameter
(exhaust)
23.000–23.021 mm (0.9055–
0.9063 in)
5. Calculate:
• Valve lifter-to-valve lifter case clearance
NOTE:
Calculate the clearance by subtracting the valve
lifter outside diameter from the valve lifter case
inside diameter.
Above 0.072 mm (0.0028 in) → Replace the
defective part(s).
a
5-29
Valve-lifter-to-valve-lifter-hole
clearance
0.026–0.059 mm (0.0010–0.0023
in)
EAS23930

CHECKING THE PUSH ROD COVER

1. Check:
• Push rod cover
Cranks/damage → Replace.
• Seal
• O-ring
Damage/wear → Replace the seal and O-
ring as a set.
EAS23980

CHECKING THE DECOMPRESSION SYSTEM

1. Check:
• Decompression system
NOTE:
• Check that the decompression pin "1" projects
from the camshaft.
• Check that the decompression cam "2" and de-
compression pin "1" moves smoothly.
1
2. Check:
• Decompression cam
• Decompression pin
Damage/wear → Replace.
ET1D71031
CHECKING THE DECOMPRESSION CAM
SPRING
The following procedure applies to all of the de-
compression cam springs.
1. Measure:
• Decompression cam spring free length "a"
Out of specification → Replace the decom-
pression cam spring.
Decompression cam spring
Free length
20.0 mm (0.79 in)
Limit
19.0 mm (0.75 in)
CAMSHAFTS
2