Overheating???

[Willy]

Hi guys, hoping someone can help me out here. I have a 1991 Merc 60 horse and the motor runs great. However, if I let it sit and idle like backtrolling or something, the overheating alarm goes off. The thing pumps water good and I don't know what is wrong. Do you think it's just a sensor, or is it really overheating?

Thanks for any help anyone can give.

[ChuckN]

I would guess a new water impeller (pump) is in order.

When was the last time you replaced the water impeller (pump)? It is recommended to change them every few years.

The water impeller is rubber and over time it gains memory and stiffens up. If the water impeller is worn out it will not pump water with enough pressure to cool the engine for long periods at idle, but it can still discharge water. At higher RPM's it will pump water with enough force to cool the engine sufficiently.

It is a relatively easy task to replace these and shouldn't break the bank if you have a mechanic do it for you.

[Willy]

Thanks Chuck, I figured it was probably the water pump but with it still spitting water, I didn't know what was going on. That sounds about right, thanks. You think I could do it myself, or how much would it cost you think?

[ChuckN]

It's quite easy to replace. Cost of a new impeller kit (new gaskets, etc.) is around $45 when I did my Merc.

To have a mechanic do it, around $150 I understand.

Go to Google dot com and do a search with these terms "replace water impeller". I found several detailed instructions in there, with pictures even.

[Pro V Dlx]

I had a simaler prob. with my Evinrude,It turned out to be a thermostat.I had it repaired last week, now it runs great,its better to be safe than sorry.Good luck!

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Pro V Dlx