Oil Pressure Question

[nyvoyager]

I am finally back in the water since 2018 with a new to me engine and mast...long story which I won't get into.
The engine appears to be a very clean low hour engine and runs perfectly, except for one concern.
When I start it, the oil pressure comes right up to 40 psi.
After it runs for awhile and it is up to temp and I rev it (I haven't gone anywhere with it yet) the oil pressure fluctuates, dropping as low as 20 psi and then coming back. Is this more then an adjustment? Hopefully it is not a bearing issue?
Yes I got paint happy. LOL
Thanks in advance

[JOHN COOKSON]

Sounds like the oil pressure adjustment needs attention.
The oil pressure adjustment consists of a ball in a orifice, spring that pushes on the ball, and a adjustment screw that pushes the spring.
If the spring tension bounces around the oil pressure also will bounces around. Take the adjustment screw and spring out to see if the spring is worn or what is happening. You can get the ball out by starting the engine and letting the oil pressure push the ball out into a rag.
Some times the seat where the ball sits needs dressed down. MMI sells a tool for this. Ken at MMI should be able to help -give him a call.

ex TRUE GRIT

[nyvoyager]

Thanks John - I'll try to have a look this weekend

[Mo]

Agree with John, I sorted one of those out about 2 months back. Just make sure you clean the threads on the "stud" where the lock nut is. It's difficult to make a good and accurate adjustment if the stud is full of corrosion or paint.

Sounds like your oil pressure is coming up with rpm? That would be a good indication that your bearings are good.

[nyvoyager]

I really need to confirm.
My sense is it is "bouncing" but the initial drop is when I rev it.
Not making any unusual noise and actually sounds great - so I'm optimistic.
Thanks