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Trouble verifying oil pump operation after banjos replaced

Posted: Wed Jul 02, 2025 5:54 pm
by Madbuffalo
Before reattaching the banjos to the engine I've attempted to verify oil flow by spinning the pump via the starter, but am not seeing any oil coming out. Does the starter just spin the motor too slowly to notice? I would have expected at least to see some oil beading up in the banjos.

I've primed the lines with a syringe and bled the pump.
Below the pump I've double checked that the shaft pin & o-rings are all in place.
Currently there are no spark plugs, carbs or exhausts mounted so the starter aught to be spinning as quick as it can... maybe just not enough?

Lately I've only been able to get in a few hours per week in the garage and this project has me feeling defeated.

Re: Trouble verifying oil pump operation after banjos replaced

Posted: Fri Jul 04, 2025 12:15 am
by Alan H
Can't remember exactly on 'spin speed' of the starter, but I think the pump only delivers one 'squirt' of oil every 63 revolutions of the engine. I did similar with my 550J, but it was a very slow process. I over oiled all the crankshaft parts before fitting barrels & head though.
Put a bit of 2t oil in the first half gallon of petrol too - every little helps, as the old lady said when she pee'd in the sea......

Re: Trouble verifying oil pump operation after banjos replaced

Posted: Fri Jul 04, 2025 12:57 am
by badgereng
Did similar procedure as Alan when I rebuild my GT500. Overoil all sliding parts and add 2t to the IV drip tank ready for blast off.

I’m not familiar with kettles but I was able to remove the oil pump and spin it using a battery drill till the oil lines were full to prove delivery to the banjos.

Re: Trouble verifying oil pump operation after banjos replaced

Posted: Fri Jul 04, 2025 10:28 am
by Madbuffalo
Thanks guys for the insights. Running mixed fuel to start sounds like a good extra safeguard. I'll try turning the oil pump with a drill and report back once I'm able.