1982 Johnson 140HP bubble back over heating

sgtallen414

Cadet
Joined
Jun 12, 2019
Messages
7
OK, need some help on this one.... what am I missing here. lol! I have a 80-82 not sure of exact year of motor 140hp bubble back. I have put a new impeller on it and a new thermostats.. The motor starts and runs, but runs hot after about 2 mins or about 100 yards at the lake. It is shooting hard pressure out of the hole, and the water coming out of the hole is hot! so why is it getting hot if the water is coming out like it should excluding it shooting out at a high pressure? I took off the head on one side and noticed that it did not have the little rubber plugs that go in the block so I put some in. still new to the boat world, and read that some have them and some don't. but even before I put them in it was running hot. and help would be great!
 
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racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,502
Those rubber hoses / plugs guide the water around for proper water flow.-----Head gaskets are also marked and can only be installed with arrow pointing towards exhaust between the cylinders.----Stop running this motor till you sort this out.
 

sgtallen414

Cadet
Joined
Jun 12, 2019
Messages
7
Those rubber hoses / plugs guide the water around for proper water flow.-----Head gaskets are also marked and can only be installed with arrow pointing towards exhaust between the cylinders.----Stop running this motor till you sort this out.

I know the head gaskets are on the right way.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,502
Sorry, I did not know that the head gaskets were on the right way.------I did not have your motor in front of me !!
 

Johsnson Outboarder

Seaman Apprentice
Joined
May 26, 2019
Messages
37
i had the same issue and it caused other things to break by running it hot. The thing that worked for me is taking off my lower unit completely and getting a water hose and filling up the water pipe until water comes out the thermostat hole/s. Once I did that, I put my finger on the water pipe and filled the engine with water through the thermostat openings until it didn't take any more water and let it go watching for something to come out other than water. Basically do your best to flush it out from the bottom and from the t stat openings. Good luck! Hope that helps.(of course that's assuming your thermostats are working properly) Try testing them out on a stovetop if you haven't already done so.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,502
Johsnson-----I think the 82 model is totally different from your looper model.
 
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