I have a new to me Fountain sportfish with a 525 efi. I just replaced the factory headers with Hurricane Lites. I removed the restrictors and followed all the plumbing instructions. The headers are just warm to the touch at idle but get very hot while cruising. So hot I burned my hand when I touched them. I replaced the raw water pump just in case and there was no change. I'll take a heat gun out on the next run but can someone give me a temp range I should be looking for? I'm running in water that averages 60 degrees.

Amy pictures of how its hooked up?

It's not letting me post pics as I'm new to the site. I just have the raw water hoses hooked up on the main header intake and the little "U" shaped hoses hooked up to the thru hull pipes. There's no leaks anywhere and there's plenty of water coming out of the exhaust at idle. I'm running Corsa silencers on the exhaust which seem really restrictive looking at them but the engine seems to run fine with them.

this what you are running ? looks to be a direct replacement for the CMI sweepers




https://www.hardin-marine.com/p-1044...in-finish.aspx

Yes that's correct. Only difference is they eliminate the overflow hose that runs up to the bottom of the thru hull pipe. So they have all the water running through the headers. They also recommend removing the restriction plugs that mercury advised using in a service bulletin that came out when all the headers started leaking.