Piston Pin And Small End Bearing; Crankshaft - Yamaha 20C Service Manual

POWR
INSPECTION
G63000-0

PISTON PIN AND SMALL END BEARING

Cleaning
1) Use a soft brush and solvent to clean the parts.
Inspection
1) Visually inspect for surface defects, breakage,
scratches and pitting. If it is decided to replace
the small end bearings, replace them all.
G63500-0*

CRANKSHAFT

Inspection
1) Place the crankshaft on a crankshaft-aligner or
on V-blocks.
2) Using a dial gauge, measure the connecting-
rod axial play.
Maximum axial play:
2.0 mm (0.08 in)
If this axial play is greater than the maximum
axial play, disassemble or replace and assem-
ble the crankshaft assembly.
3) Using feeler gauges, measure the connecting-
rod side clearance.
Connecting-rod side clearance:
0.200 – 0.700 mm
(0.0079 – 0.0276 in)
If this side clearance exceeds the specification,
disassemble or replace and assemble the
crankshaft assembly.
4) Using dial gauges, measure the deflection.
Maximum deflection:
0.03 mm (0.0012 in)
If the deflection is greater than specified maxi-
mum, correct the alignment by use of a copper
hammer and a wedge.
5-20
E