Yamaha VMX12H Supplementary Service Manual page 150

INSPECTION AND REPAIR
2. Measure:
Valve Compressed Force:
Valve Lifter
1. Inspect:
Valve Installation
1. Lubricate:
2. Install:
-0
NOTE:
Install springs with wider-gapped coils facing
upwards, as shown.
Larger pitch
Smaller pitch
force (installed length)
Out of specification Replace.
-
Outer: 13.3 15.7
at 33.8 mm (1.331 in)
Inner: 6.29 -7.39 (13.9
at 31.8 mm (1.75 in)
lifter wall
Scratches/Damage
and cylinder head.
Valve stem
seal
H igh-Quality Molybdenum Disulf ide
Motor Oil or Molybdenum Disulfide
Grease
spring seat
seal
springs
spring seat
retainers
34.6
16.3
Replace both lifter
3-26