Overheating

[jwpope]

I have a 70HP 4 stroke. I run in a lot of shallow sandy and silty water. The pee tube gets stopped up quite a bit so I clean it out on a regular basis. Lately when I run at planing speed, I get an overheat warning and the engine speed cuts back. The first time this happened, I took the pee tube out to clean it (just in case) and lost it overboard. I went on about my business of fishing (there was a good stream of water coming out) I replaced the pee tube, it shoots a strong stream of water, however when I get up to planing speed after about 5 minuntes I get the overheat warning. I took the pee tube plug back out and I did not get the warning. I came back to the dock and took out the thermostat and put the pee tube plug back in. After for about 5 minutes on a plane I get the same situation. The water was warm coming from the pee tube, but not hot. I took it out and ran it some and no overheat warning. Anyone know what might be going on?

[mitch]

have you replaced your water pump impeller as it could be worn

water pump break down

http://www.boats.net/parts/search/Su...UMP/parts.html

[jwpope]

I have not. Would it be shooting a strong stream of water if the impeller was bad?