Bummer!

[nipper]

Are you sure it really got that hot. The reason I ask is that put on the flush muffs and fired up my 20' Formula I am trying to sell after it had a 3 plus year nap. All seemed fine but the temperature gauge almost immediately pegged out on hot so I shut it down and thought great, I need to replace the impeller. This was even though water seemed to be coming out of the exhaust ports. A couple hours later a friend came by and he talked me into firing it up again. I turned the key and the temperature gauge was still pegged out on hot. Hmmm. So, I started the engine and we monitored the temperature by putting our hands on the risers and manifolds and it was running cool as a cucumber and stayed that way for 15 minutes or more. So, maybe I have a bad temperature gauge, and maybe you do, too.

[i4110peter]

Yes I took the muffs off, although I'm not beyond making that kind of mistake. I'm also sure that the engine got that hot, cause I could smell oil cooking and could not touch the engine at all. New thermostat today and we'll see. I will have this fixed soon!

[i4110peter]

Well, looks like I will have to pull the lower unit to check the impeller and I think i will pull the water pump while I'm at it just to make sure. Any other suggestions? I put i a 140 degree thermostat and the temp went up to 180 and was still going when i shut down.

[tsubaki]

You're going the route I'd take.
First the t-stat and then the impeller.
But me being an outboard guy it would be reversed.

Did have an interesting problem one time with Guinea Wasps building a nest in the foot preventing the water uptake.