What sort of oil pressure should I be seeing on the ZX9 B engine I have when it is idling and up to decent temperature?

When I start it it has good pressure but as it warms up this decreases until when the oil is up to a decent temp the pressure on the gauge is down to less than 10 psi (swoosh gauge and brand new sender). This is the red area of the dial and after a really long run so getting pretty hot its right at the bottom showing 2 or 3 psi. If you rev it it immediately jumps back up to 30 ish psi.

I can get some more exact figures tomorrow but just trying to get a feel for if there is something wrong? All seems fine otherwise.

Does this sound right? My old 911 was similar but not used to bike engines.

Rich

The oil pressure will obviously drop as the engine oil gets hotter and thinner, however if your guage isnt telling lies, 3 psi is way to low at tick over bearing in mind that the cranks soft metal shells are supposed to be floating on a bead of pressurised oil. I would verify the pressure with and alternative guage and if it still says the same I would be pulling down the motor to check shells , oil pump etc. I would avoid running it until I had checked that reading because as it stands it is rebuildable but if it is shells starting to wear, you could get to meet a conrod in the not to distant future.
If you are still having problems give me a call on 01449 736633
Regards
Andy

as above

Gentlemen, thankyou.

I will be checking this out this week.

Not what I wanted to hear but what I suspected.

Cheers

Richard

OK so finally got another oil pressure gauge, this one an analog with capillary tube and its still showing low pressure going down to 0 psi at tickover when the oil temp is at about >55 degC.

So obviously as above this is not good and we will take start by taking out the engine and remove the sump (which is shortened) and look at the pickup and at the pump and pressure relief valves. I have a spare engine with a knackered gearbox but its oil pump looks good and there are 2 spare pressure relief valves.

Question is if I replace these things and try it again the manual says at 80degC and 4000rpm it should see 44-53psi.

What pressure do you see at tickover when up to temperature?

Anyone with a similar engine advise what pressure they see (given its an older engine with unknown mileage)?


Rich