overheat alarm

Engine: 1998 Force 90 Hp
two stroke
Problem: Overheat alarm goes off after idling in forward for 15 - 20 minutes. I've climbed down w/ it in neutral after the alarm sound s and felt the water coming out the "pee" hole and upper exhaust. Feels hot but I can hold my hand in it for up to 10 seconds, so I don't think it's excessively hot. Put it back in forward and rev it up a little 'til the alarm shuts off. Back in neutral and check water temp again. Doesn't feel much cooler. Any idea what's wrong?
TIA,
Mike

I'd be pulling the tower end off to check the impellor if I were you. It might be worn and not pumping enough water. If it's not that, it could be a number of things. Good luck.

I had a similar problem with my old 60hp Mariner and it ended up melting a piston. I rebuilt the motor from top to bottom, carb kit, new piston, new water impellor, fuel pump rebuild kit etc.... You get the picture. Motor was running like new till I was halfway across the lake and it died again. Pulled the plugs on it and found the dreaded metal filings all over one of the plugs. Ended up selling the boat for more than I paid for it with a running motor and got a brand new princecraft for the same $$$ I would have had invested in the old boat had I kept it and bought a new motor.

could still have a bad impeller, when was it changed last? pee hole temp really is not a good indicator of flow.

Thanks for the reply,BDavis. I don't think it is the impeller because it just had a new lower unit installed when I bought it a month ago and they changed the impeller while it was off.It hasn't sucked up any sand or mud or started dry. Next time I take it out,I'll take my test thermometer and check the water temps as I did before. I'm no outboard expert,but I'd think if the impeller was getting bad it would overheat when running at higher RPM.
Thanks,
Mike