Overheat problem on 140 Johnson...

[randymbtech]

Hey guys,

I need a little help with my 1986 140 horse V4 Johnson. The temp comes up as it idles, almost to 190 degrees on the temp guage. I replaced the water pump last year, and didn't put any hours on it. I just replaced the thermostats this weekend, but it's still heating up at an idle. If you throttle it up and get on plane, it cools down and runs great. It has a weak stream out of the pisser, which makes me think I have a pump problem, but I'm not sure. Any help would be greatly appreciated. Thanks.

Randy

 

[ezeke]

Re: Overheat problem on 140 Johnson...

Have you serviced the thermostats?

The Tell tale has a 1/8" outlet at the engine running to a 1/4" outlet at the lower cover, so the flow will never seem very high on those motors unless you change the fitting at the lower cowl.

The Telltale will let you know if the waterpump is functional, but will tell you nothing of the flow of water through the cooling passages of the engine.

 

[randymbtech]

Re: Overheat problem on 140 Johnson...

Yah, I just replaced both thermostats and diaphrams last weekend. I think I might have overlooked something when I changed the water pump. I think I'm going to drop the lower unit this weekend and check it out.