The oil pump can be completely assembled on the bench or piece by piece over the pinion shaft. Either way is fine as long as it is assembled with plenty of assembly lube or clean oil and there is never any binding.
Install the oil pump o-ring into its location in the crankcase. This o-ring is an intrical part of the oil system. If the o-ring doesn’t seal correctly, there is a good chance that the motor will have low oil pressure, especially at idle. Lube the o-ring and pinion shaft with clean motor oil and push the oil pump body into position.
Lube the inner cam bearings, cam plate bearings, cam lobes, cam plate bushing and cam gears. Correctly position the cam plate and cams into the cam compartment. Apply Loctite to the support cam plate and oil pump retaining screws. Loosely install screws. It is not necessary to have or use the oil pump alignment pins. They are helpful but the oil pump can also be correctly centered using its own retaining screws.
Follow the factory torque sequence to snug, then loosen (back out 1/4 turn) all of the retaining screws. Turn the motor to definitively center the pump. Snug and final torque the support plate screws according to the torque sequence. Then, continuously turn the motor while final tightening the four oil pump screws according to the factory torque sequence.
Next, Mike will prepare to install the cam and pinion gear on this gear drive assembly.