OK....this past summer was my first summer with a boat. I had alot of problems with it this summer and hope to have all the bugs worked out so I can actually enjoy it next season. Like I said I am new to boating. I had alot of overheating problems. Changed out the Raw water pump and T-stat. And still getting hott. When I get up to about 4R's It will run for a short time and throttle will cut out. Come off of the throttle and the boat is still running. Weirdest thing. Does anyone know what this may be a sign of. Oh I am running a Merc 502 EFI with Bravo 1 drive. Looking forward to next season.

The engine (ECU, computer) goes into safe mode or "limp Home mode" which will allow for low RPM running to get you back to shore. On the overheating thing, check all your hoses for a blockage, the I'd do a compression test to make sure you don't have a blown gead gasket. Any white smoke or excessive steam from the exhaust? What does the temp gauge say?

It's your money. Pull it now or pull it later. There's something internally causing excessive heat.

I would check that the manifolds and risers are not clogged up. Usually, they act just like the problem you are describing..

Did you change the circulating pump or the Impeller kit? Sound like you could have impeller pieces inside the passages somewhere. (I did but we were able to back flush them out)

best way to get ready for next year is to freshen up the motor and add more doggies, and build a spare while your at it...you might want to get a spare drive as well