Oil Pump Question Z1. 750

[Ian Hand]

My engine is running well onthe test bench and shows no signs of anything wrong. It starts easily, idles nicely fully retarded and runs freely when fully advanced and throttle opened.....BUT, my oil pump is showing 80 PSI on the guage. It's flowing through the return line OK with a few bubbles and there are no oil leaks squirting out anywhere like you might expect with 80 PSI in the system.   Has anyone experienced this phenomena before.  Have I put some ball valve in backwards somewhere,   I did surface grind the pump plates and gears, gave them the correct clearance..... (a guess based on my hydraulic experience) put it all together with a sealant and tested the flow with a cordless drill and all seemed fine.  It's a new guage and maybe, like everything else, I can blame it on the Chinese Quality. Has anyone any suggestions please.

[graeme]

Hi Ian

Is this the pressure when the oil is cold? I have a T160 Trident, and that shows 100psi oil pressure at idle when cold, but settles down to 30psi once warmed up.

Cheers, Graeme

[Ian Hand]

Thanks Graeme,
The pressure does not seem to go down much although I have not run the engine on the test bench long enough to warm up the oil in the feed tank.  I am not willing to risk damaging the engine if I have replaced a bronze bush and not lined the oil feed holes up or something silly like that.  I have a test guage which I will try in the next few days.If it settles down I will be happy, if not I will strip the engine down again and check everything.  The bike is only 2 days more work to be a rider and I would be really angry with myself if it blew up on the first ride due to some dumb mistake.

[Ian Hand]

OK, so yesterday I discovered the dumb mistake.  There are 2 ways to assemble the crankshaft, one way lines up the oil ways and the other does not.   I chose the latter.  At lease I will sleep at night now.