Is my Oil Pump serviceable - Advice please

[LTGTR]

I am building a spare motor and cant decide/confused if the oil pump is serviceable.
Inner to outer rotor clearance - 3.5 thou. (some specs on the forum - no specs in my 77 D Yamaha manual).
Side clearance (straight edge across housing, feeler guage between straight edge and top of rotors) - 3 thou.
Thickness of rotors - .314"
Assembly spins smoothly.
No gouges, grooves or visible wear.
Seems like im on the outer limits - new pumps from Mikes seem to come with hassels.

 

[Raymond]

Silly question, but does your oil pump rotor look worn? Likewise the housing it runs in?

If not, and if it was me, I'd probably reassemble. Unless of course I already suspected poor lubrication. You can check that oil is circulating once the engine is back up and running. For example, through the tappet covers, or by loosening the filter cover on the r/h side.

Nobody else has answered, but this reply might pique further responses.

 

[LTGTR]

Raymond - thanks for the reply. Yes, I think your idea is the way to go - there is no visible wear on the rotors or the housing.
It bothers me a bit that my measurements are on the limit of the few specs I can find.
I will go with what I have and do my best to see if I have good lube to the top end before I fire the motor.
Regards Ray.

 

[Raymond]

When I started mine after a rebuild, I left ignition off and kicked and kicked till I was sick of it to get oil through the system before I started the engine. Probably not necessary if you use plenty oil assembling it. But we can't seem to help pandering our bikes . . .

 

[LTGTR]

Raymond - I read/researched a lot about checking for a good lube supply before starting new motor.
I think I may have read your post about all the kicking you did.
The research I did tells me to use the starter motor, plugs removed, Jim even suggests backing valve adjusters all the way off, and it will still take 30 seconds.
So I think your mention of assembly lube is important.
I think it was egggary that suggested cracking the union at the base of the oil delivery pipe (to the top end) to see an "earlier" signal that you have lube.
Maybe even leave it off and be prepared to switch off as soon as you see oil.
These old bikes sure test our patience.
Regards Ray.