Every boat I ever had would run 220-230 after running hard . This phantom I just bought will hit 260. When you back it down it cools off like it should. Water temp never goes over 160-165 deg. It has merc. 502 mpi 415 hp. oil coolers and the engines make 500 hp. I'm thinking that the stk 502 coolers are to small and I need to go to something like a 500 /525 cooler. I'm going to switch to mobile 1 15/50 that will lower it a bit.

Call Dennis at Innovation

I think I know wy!! The props that came with the boat have had cup added and the engines only pull 4700-4800 rpm's. That's wright where the engines make almost peak torque at. they need to go 5100 rpms.

That's too hot. Try to keep it under 220.