First, engage the oil pump chain [A] to the gears, and then install the oil pump drive gear [B].
Turn the “OUT” mark [C] to outside.
Apply a non-permanent locking agent to the oil pump drive chain guide bolt and the oil pump drive gear bolt.
Tighten the oil pump drive gear bolt [D] temporary.
The oil pump drive gear bolt is left-hand threads.

Oil Pump Drive Gear Removal/Installation
Oil Pump Drive Gear Shaft RemovalShift Fork/Gear Groove Wear Inspection
Measure the thickness of the shift fork ears [A], and measure
the width [B] of the gear grooves.
If the thickness of a shift fork ear is less than the service
limit, the shift fork must be replaced.
Shift Fork Ear Thickness
Standard: 5.7 6.0 mm (0.224
0.236 in.)
Service Limit: 5.6 mm ...
Battery Installation
Visually inspect the surface of the battery container.
If any signs of cracking or electrolyte leakage from the
sides of the battery.
Put the battery into the rear fender
Install the band [A].
Connect the positive (+) cable [B] (red cap) to the positive
(+) terminal first, and then ...
Piston Wear Inspection
Measure the outside diameter [A] of each piston 5 mm
(0.20 in.) [B] up from the bottom of the piston at a right
angle to the direction of the piston pin.
If the measurement is under service limit, replace the piston.
Piston Diameter
Standard: 75.959 75.974 mm
(2.9905 2.9911 in.)
...