I just recently bought a 1997 32' Fountain. It has twin 500hp (carbed) engines. Just recently, my water temperature is reading so high that it triggers the alarm to go off! This boat is less than a week old. Am I going to be emptying my pockets to fix this?

Was told that it could be a few simple things like thermostat or just flushing the lines.

Oh yeah, it's only the port engine.

Not likely. Are you sure the impeller is new? Is the motor really getting that hot? Can you put your hand on the exhaust manifold? It is either not getting water or the gauge is screwed up.

I felt the braided hoses where the water flows through. It seemed much warmer than the starboard engine. The boat has about 200 hours so the impeller is not new. I was actually told that could be the problem too.

Is there a standard for replacing impellers after certain hours? What could cause it? I was cruising about 3000 rpm for about 20 min when the alarm first triggered.
Is this a hard/expensive repair?

I am almost sure it is your sea pump impeller. Were you recently traveling in low waters? You could have picked up some mud or sand and it might have hurt your sea pump and the first blockage would be your oil cooler which would be located on the top of your bell housing. I would change you sea pump every 50 - 100 hours or once a year ... as preventive maintenance. Also,a good tip would be to remove the whole assembly off the motor which consists of the fuel pump and sea pumpt and inspect the cam shaft lubrication for the fuel pump. There should be oil in there and not gas, if there is gas in there than that is another problem. I love boating....

Isn't the impeller in the outdrive? Not too sure I'd be comfortable tinkering with that.
I'm not really sure how to check if a thermostat is bad or not. Everyone tells me it's easy. It's located in the front of the engine, where the rubber hoses enter the engine correct? Just pull the hoses off and it's right there correct?
Is the 140* the best thermostat for the 500HPs?

Vendetta....
Since I ride in Lake St. Clair, shallow water is an everyday occurance for me. Thanks for the info. Hopefully I'm not running into more serious problems......

Like everyone else has said it is almost defentily your impeller. The impeller and housing chould be changed though not just the impeler. You can get it all as a kit. It is much easier to remove the 2 bolts that hold the whole thing onto the front of the engine and service it on the bench once you get it off you will see that it is pretty staight foward. let us know if you have any problems.

Hey did anybody mention its probably the impeller....

If the impeller is bad when you take it apart be sure to flush the lines, chunks of the impeller like to get stuck in the coolers which will cause flow problems.

Thanks everyone for the info! I'm going to check the impeller and thermostat. Seems like this should be a fairly easy fix!
I'll let you know if I run into any probs!

Thanks again!