at high rpms it used to got up to about 85 or 90.......when it goes above 75, it backs off and stays at 75........anyone know what's going on?

 

Bearings starting to wear out?

 

There is a releif valve in the block, accessible when the head is removed.
The spring might be worn. I think if the bearings were wearing out, then the oil pressure would have difficulty peaking, and then "backing off" as you said...
Could also be a multitude of other relief valves.
BTW, how did you install your oil pressure guage?

 

i have a electical gauge and used the 3 ft steel braided line and mounted the sender on the fire wall...........so should i be very worried about this problem?.......can it cause any damage?

 

Have you checked your oil level? It may seem obvious but that could be the issue.

If that looks fine you can get an oil pressure gauge(different than what you have)

Fit where Oil Pressure switch is.

10 psi minimum at ldle
50psi minimum at 3,000 rpm

If pressure if not within spec you oil pump most likely needs replaced.


[Modified by machaf, 4:55 PM 1/1/2002]

 

that is the prefer way of mounting the sender.

 

thats the highest the gs-r oil pressure goes up to.
i have rigged my iol pump and i only get 85 psi