what should oil pressure be on a Apex?

[Tuf-Skin]

Hello all. this is my first post on your forum. Thanks in advance for any help.

I have a 2006 Apex engine that has been transplanted into a RZR side x side.
Sometimes it throws a code 30 (low oil pressure) when its cold on start up.
I installed a pressure gauge and it is reading between 40-60 psi on start up, but if I let it idle it starts to fall and will go below 10psi and throw the code 30 and shut down.
If I keep it above idle the pressure stays in the 40-60psi range.
Do these symptoms suggest I need a new oil pump?

thanks

 

[Roadrider]

Could be the pressure relief valve. If the filters have
a bypass that is a very common cause in a car. I just
changed a filter in a dodge dakota to fix the same
problem.

 

[Tuf-Skin]

where is the pressure relief valve?
I read in the manual that it is set at 78.2psi. but if it is malfunctioning that could cause the pressure drop.

I am using a Yamaha oil filter.

 

[Roadrider]

And Idle is 7.1 psi hot @ 1450 rpm. So below ten is no problem. The relief valve is in the motor, probably
at or in the pump. The by pass valves that filters
have are in the filter. I don't know if the yamaha filters
have one or not. A quick google search suggests it does.
The easiest thing to do is change the filter. The valve works on
pressure differential is why they act different on start up and then warm.

 

[Tuf-Skin]

I just put a new oil filter on.
mine is set to idle at 2000 rpm.
I will check tomorrow and see how low the pressure is getting. maybe it is going below 7psi.
I just saw it drop below 10psi and then it shut down with the code 30.

after it is warmed up it usually doesn't shut down.