Mercruiser 140 with 3.0 overheating

[ggautney]

I have an old 1970 Mercruiser 140 that is overheating when I am idling but is fine when at higher rpm's any suggestions?

 

[rogerwa]

Re: Mercruiser 140 with 3.0 overheating

Classic presentation of a bad impeller or waterpump problem.

That is where I would start.

 

[Don S]

Re: Mercruiser 140 with 3.0 overheating

In a boat, the impeller is the first place you start on any overheat problem.

 

[ggautney]

Re: Mercruiser 140 with 3.0 overheating

How big of a job is it to change the impeller and is it the water pump that sits directly on top of the motor where all of the hoses come into and go out to the motor? Thanks

 

[DJ]

Re: Mercruiser 140 with 3.0 overheating

The water pump is in the drive. Don't attempt it without a manual and a strong back.