Yamaha YZ426F(M)/LC Owner's Service Manual page 350

OIL PUMP
INSPECTION
Oil pump
1. Inspect:
Oil pump drive gear
Oil pump driven gear
Rotor housing
Oil pump cover
Cracks/wear/damage → Replace.
2. Measure:
Tip clearance a
Between the inner rotor 1 and the
outer rotor 2.
Side clearance b
Between the outer rotor 2 and the rotor
housing 3.
Out of specification → Replace the oil
pump.
Tip clearance a:
0.07 ~ 0.12 mm (0.0028 ~ 0.0047 in)
<Limit>: 0.15 mm (0.006 in)
Side clearance b:
0.03 ~ 0.08 mm (0.0012 ~ 0.0031 in)
<Limit>: 0.15 mm (0.006 in)
3. Check:
Unsmooth → Repeat steps #1 and #2
or replace the defective parts.
ASSEMBLY AND INSTALLATION
Oil pump
1. Install:
Oil pump drive shaft 1
Washer 2
Pin 3
Inner rotor 1 4
NOTE:
Fit the pin into the groove in the inner rotor 1.
4 - 58
ENG