Looking for help on 500 EFI that is overheating
 

Posted the following on the tech area but didn't get help. I'm hoping a fellow Formula owner can weigh in

Tried back flushing and it won't clear. Can get through the oil cooler with flush but no further. From the diagram it looks like the only thing left is a fuel cooler and it looks like it's under the engine. The boat is a 353 formula. Any idea if the fuel cooler is accessible or if it's toward the front of the engine? I even tried back flushing with a pressure washer and the hose literally started to balloon so I backed off. Any other ideas? Hoping not to have to have the engine pulled.

Cool fuel located under front of motor and you also have ps cooler if that motor is equipped with ps.

Cool fuel is first out of the raw water pump and under the front of the motor

Thanks guys. I will try to get under there. Hard to imagine the pressure washer wouldn't blow it out

Now I am really stumped. I can get water to flush from the fuel cooler up to the oil cooler (the way water normally flows) but when I try to flush the other way it wont go at all. My other engine flushes all the way through so I started wondering if this engine had a power steering cooler if there was some kind of a one way valve on it. Does anyone have any ideas?

It turns it there is a blue pressure valve in between the power steering cooler and the oil cooler and sure enough it only flows one way. It is a one way pressure valve. I guess my other engine is letting water back flow and shouldn't which completely threw me off when that one would. Looks like its a Tstat issue. Maybe this will save someone else a bunch of work.