Oil Pump; Primary Drive; Clutch - Yamaha XZ550RJ 1982 Service Manual

The connecting rod numbers are stamped in ink on
the rod.
Proper bearing selection is made by subtracting the
crankpin number from the rod size number. Use the
color code to choose the proper bearing.
Example:
Rod No. - Crankpin No.
= Bearing No.
4 -1=3
No. 3 bearing is brown. Use brown bearing inserts.
Bearing color code
No. 1
No. 2
No. 3
No. 4
No. 5

Oil pump

1. Measure the rotor width on both troch-oid
gears. If the measurement exceeds specifi-
cation, replace the pump.
Rotor width:
Crankshaft pump:
Transmission pump:
2. Measure the clearance between the rotor
and housing. Replace the pump assembly if
the clearance exceeds specifications.
Blue
Black
Brown
Green
Yellow
6mm (0.236 in)
4mm (0.157 in)
Rotor-to-housing clearance:
0.03 ~ 0.09mm (0.0012 ~ 0.0035 in)

Primary drive

The drive gear is mounted on the crankshaft; the
driven gear is mounted on the transmission main
axle and integrated with the clutch assembly.
Primary reduction ratio
No. of teeth
Drive Driven
33 73
1. Check the drive gear and the driven gear for
obvious signs of wear or damage from for-
eign material within the primary case.
2. If the primary drive is excessively noisy dur-
ing operation, replace both the drive and the
driven gears.

Clutch

Clutch housing
1. Check the dogs on the clutch housing. Look
for cracks and signs of galling on the edges.
If damage is moderate, deburr; if severe,
replace the clutch housing.
NOTE:
Galling on the clutch plate splines will cause erratic
operation.
Ratio
2.212
65