97 40Hp Merc. Motor overheating any ideas?

[bowstalker]

So I have a 1997 40HP 2 stroke. Due to low amount of water out the [PoorWordUsage] I bought and changed out the impeller. The housing looked good I think. So the new impeller did nothing to help and the situation has started getting worse. Now if I run it wide open the high temp alarm goes off. 1/4 throttle and higher and I get only steam out of the [PoorWordUsage]. I checked suction at idle by putting my hands around the lower unit area intake fins and it sucked very well or atleast for what I figured. I also disconnected [PoorWordUsage] hose at exit location and blew, seemed very easy to blow through, don't know if that tells me anything anyways. So I am sort of lost, any suggestions would be great. Thanks!

[CAMAN]

Probably time to replace the thermostat

[Valv]

If you are new to this maintenance repair it might be you missed something or put it together incorrectly.

Did the pump housing really look good ? Did the cotter key stay in the slot and not fell down the holes below (this impeller won't spin) ? Did you put the plastic tube back in, and did it go inside the hole correctly when you reconnected lower unit to motor ?

All these questions need a sure answer. I would not use motor again, remove lower unit one more time and check it out good. One hint before you disassembly the water pump, if you can spin the driveshaft by hand, it means your impeller is shot again or it's not spinning due to missing cotter key.

Let us know

[bowstalker]

Thanks for the help guys. I thought I spoke with a mechanic and my motor doesn't have a thermostat, does that seem right? I have changed the impeller two times. The second time I didn't have the hose lined up and no water came out at all, if I was missing the key I don't think I would get any water either. Oh well Maybe it is just time to buy a new housing and try that. Does the fins or cooling area of the motor ever get clogged. I don't want to waste the money on a new housing if maybe something is blocked? Is there any way to test for blockage?? Again I appreciate the help.