Yamaha FT50C - Checking the Crankshaft Main Journal Oil Clearance

62Y5A11
5-42
1
2
3
4
5
6
7
8
9
2. Measure the crankshaft runout. Replace
the crankshaft if out of specification.
Checking the crankshaft main
journal oil clearance
1. Clean the bearings, main journals, and
bearing portions of the crankcase and
cylinder body.
2. Place the cylinder body upside down on
a bench.
3. Install half of the bearings
1
and the
crankshaft
2
into the cylinder body
3
.
CAUTION:
Install the bearings in their original posi-
tions.
NOTE:
Insert the projection
a
of the bearing into the
notch in the cylinder body.
4. Put a piece of Plastigauge
®
(PG-1) on
each main journal parallel to the crank-
shaft.
NOTE:
Do not put the Plastigauge (PG-1) over the
oil hole in the main journals of the crankshaft.
5. Install the remaining half of the bearings
into the crankcase.
NOTE:
Insert the projection of the bearing into the
notch in the crankcase.
6. Install the crankcase onto the cylinder
body and apply engine oil onto the
threads of the crankcase bolts.
Crankshaft journal diameter
a
:
42.984–43.000 mm
(1.6923–1.6929 in)
Crank pin diameter
b
:
32.984–33.000 mm
(1.2986–1.2992 in)
Crank pin width
c
:
21.000–21.070 mm
(0.8268–0.8295 in)
Crankshaft runout limit:
0.04 mm (0.0016 in)
Cylinder body