Engine Overhaul; Inspection And Repair; Crankshaft And Connecting Rod - Yamaha VMX12H Supplementary Service Manual

INSPECTION AND REPAIR

ENGINE OVERHAUL

INSPECTION AND REPAIR

CRANKSHAFT AND CONNECTING ROD

1.Measure:
Runout (crankshaft)
Out of specification
Runout:
Less than 0.03 mm (0.0012 in)
2.1 nspect:
Main journal surfaces
Crank pin surfaces
Bearing surfaces
Wear/Scratches
3. Measure:
Oil clearance (main journal)
Out of specification
0.020 ~ 0.038 mm
(0.0008 ~ 0.0015 in)
Measurement steps:
Do not interchange the bearings and con-
necting rod. They must be installed in their
original positions, or the correct oil clear-
ance may not be obtained causing engine
damage.
the bearings, main journals and
bearing portions of the crankcase.
the crankcase (upper) on a bench in
an upside down position.
the
the crankshaft into the crankcase (upper).
N O TE :
Align the projection of the bearing with the
notch in the crankcase.
- 7 -
Replace.
Replace.
Replace bearing.
half of the
upper bearings
and