502 oil pressure
 

I recently had my zz 502 502 rebuilt it is now a 542.I have it in my 2000 kachina jet boat . the oil pressure starts out at about 60 then after it warms up it will not go above 25 at any rpm. it runs at about 190 degrees. Is somthing wrong with the motor?

check the electric gauge by hooking up a mechanical one.

Is 190* the water or oil temp?

If 25 lbs is correct, then yes, you have an issue

If 190 degrees is the water temperature then it is way too high, and I would assume the alarm would start.
If it is the oil temperature I guess it is OK.
But strange with the oil pressure. It sounds like the pressure is OK when the engine is cold, but not when hot. That your oil pressure drops at idle to 25 PSI when the oil is hot sounds OK to me, but it does not sound OK that the pressure does not increase when running at higher RPM with hot engine oil.
Question is if your oil pressure sensor could be faulty when the engine is hot ?

Unscrew your sending unit,screw in a test gage and see what your oil pressure really is hot. If its actually dropping to 25 psi you have problems and you need to find them,PERIOD.What weight oil? What were yout rod and main clearences? Lets say your engine was put together at .004 or .005 rod and main,the oil pressure would be ok cold but pretty low hot BUT if big clearences or missassembly were your problem your oil pressure would drop to 0 or maybe 5 psi hot at idle, Smitty