Topic: CB750 Oil Pump shaft runout. Really?

[MCRider]

On my CB750 oil pump, I reassembeld it and in passing noticed that by pulling on the gear, I can pull the shaft in and out about 1/4 - 3.8 of an inch is that right?

Pushed in:


Pulled out:


I disassembled it, everything in place, mostly just 2 pins and the 4 rotors.

[brandEn]

I have a couple known good pumps and they both do that. Never noticed that before. Interesting.

[Elan]

Yeah I had thought I was missing a part at first. 

[flybox1]

Mine did it before and after I installed Elans kit.   

[MCRider]

Thanks for the replies! I'll worry no more.

[Ellz10]

On my CB750 oil pump, I reassembeld it and in passing noticed that by pulling on the gear, I can pull the shaft in and out about 1/4 - 3.8 of an inch is that right?

Pushed in:


Pulled out:


I disassembled it, everything in place, mostly just 2 pins and the 4 rotors.

I know this is an old thread, but I'm curious if anyone else's pump rotates with more difficulty when pushed in and easy when pulled out, the way mine does. Is that normal?

[HondaMan]

There is a 'hump' in the crankcase next to the pump gear that keeps it from moving out too far in use, nudges against the middle of the gear. They all have the movement.