Overheated?????

[Zerex]

I just bought a small bass boat with a 1992 Mercury 50hp 3 cyl and while I was trolling the siren in the throttle control went off. Now I know that this is a over heating issue so my question is why does it do it only when I troll. Is the impeller shot? Any help would be greatly appreciated. Thanks

Sorry I don't have an answer but my 1998 Mariner 50hp 4 stroke is doing the same thing. If i run at full throttle for 5 mins or more and then slow down to idle my alarm goes off aswell. I have a steady stream at all times from the telltale and I've replaced the thermostat and impeller. I also checked the water tube from the lower unit to the engine and it's clear aswell. The only thing I can think of is my impeller pump housing has a small seal that seals to the driveshaft and it was pretty worn out. But i left it cause i didnt think it would affect anything. Now that I still have this overheat I'm wondering if maybe that's the problem??????

 

[jze1212]

Re: Overheated?????

Do you have a stream coming out of the telltale at all times?? Perhaps at a lower RPM you are not getting a good flow of water thru there, which would lead me to think it is an impeller issue.. OR, do does it have a thermostat that may not be opening up all of the way? I wish my problems were that simple.. Good luck!