I have a 31 sunseeker hawk with 1994 volvo penta 502s pushing DPXR drives. overheats over 3500 rpms fresh water cooled, new water pumps, heat exchangers, manifolds and risers. need help? should I run direct strainers? thru hull and forget the drive pick ups? that's all I can come up with? any help greatly appreciated! 🙏🙏

Both engines doing the same thing?
Did they both start doing this at the same time?

I just bought the boat and it needed 2 transom assembly which I found brand new. pulled the engines and put everything back together. and ran the boat. anything over 3500 runs up temp. yes they both do same thing. very sad.

So you don't know if this problem was present before you did all that work?

I called the owner that I bought the boat from and he said he never had it overheat problem but then he also said he never took the boat over 3000 rpymes.

Funny

Connect a piece of short piece or clear hose between raw water pump and heat exchanger. Look for bubbles when running

Use a IR Temp gun to measure Temp at thermostat housing to verify the actual Temp

I will do that. thank you. what should that temp be?