Overheating issue on a 1998 Johnson 115 hp

[Wheeler wheeler]

Hello to all.....this is my first post need some suggestions......I have a 1998 Johnson 115 model # j115tslecm....I started it today and it ran hot within about 7 minutes.....the warning buzzer came on so I shut her down....waited about 20 minutes restarted and same thing occurred....overheat.....The whole time there is a strong pee stream.....anyone have a clue as to my problem.....boat has ran find since acquiring it about 4 months ago.....I do know that the water pump and impeller were replaced about a year ago....Please help!

 

[mcm4mac]

Re: Overheating issue on a 1998 Johnson 115 hp

I have the same engine on my Hydra-Sport boat. The other day I was running it outside, connected to the hose, and at idle. After a while it, too, displayed the hot engine symptoms. I felt of the pee stream water coming out and it was warm, not hot. I revved it up to about 2000 rpm and the hot display went away. Good luck.

 

[Big Fish Billy]

Re: Overheating issue on a 1998 Johnson 115 hp

Thermostat could be stuck shut, although they normally fail open, mcm sounds like his was stuck shut or a stuck heat sensor....a good toy to get next time Harbor freight has a sale is that infared temperature gun, just point and get the temp...nice tool to have.

 

[Wheeler wheeler]

Re: Overheating issue on a 1998 Johnson 115 hp

I suspect that it is the thermostats as well....this engine has 2 of them...at the bottom of the cylinder heads...to access the tstats I have to remove the lower engine housing....has anyone ever done this and if so ....how difficult is it to do? Thanks in advance for the help!

 

[Big Fish Billy]

Re: Overheating issue on a 1998 Johnson 115 hp

Looked at a couple diagrams, looks like it's at the top of the heads.... OMC, Johnson & Evinrude - CYLINDER & CRANKCASE - 1998 Johnson/Evinrude 115

 

[Wheeler wheeler]

Re: Overheating issue on a 1998 Johnson 115 hp

It is this model.....OMC, Johnson & Evinrude - EXHAUST HOUSING - 1998 Johnson/Evinrude 115

 

[Fed]

Re: Overheating issue on a 1998 Johnson 115 hp

Did it overheat in the water or on the hose wheeler?

If you look in the oem manual the only time they mention servicing the thermostats is when the power head is off. (I'm not saying they can't be done in place but it makes me wonder)

There's quite a few threads in here where people have cut access holes in the back of the pan but I'm not sure if that would be needed for your particular motor.

 

[Wheeler wheeler]

Re: Overheating issue on a 1998 Johnson 115 hp

It overheated on the hose....was at Johnson Part place and the lead mechanic said that the housing can be loosened up enough to allow the housing to drop down just a little to make the repair....got the kit today gonna give it a go on Saturday afternoon.....

 

[Fed]

Re: Overheating issue on a 1998 Johnson 115 hp

I'm not sure what housing you mean, the pan?
I'd be doing a bit more testing first, like turn the hose on a harder or stick it in the water.
Possibly disconnect the 2 rubber hoses where they go into the thermostat housing & check the water flow at that point.

Please let us know how it goes.

Boobie (member here) once mentioned using studs to line up the whole sandwich then replacing them with bolts one at a time so that may help you, I don't see how myself due to the limited space but you never know until you try it I guess.

Good luck with it.

 

[boobie]

Re: Overheating issue on a 1998 Johnson 115 hp

You can't lower that lower housing enough to do the repair. It's a matter of drilling holes in the cowling to use sockets and extensions, cutting the housing away and reinstalling it with plates and pop rivets or pulling the power head. The job is a b***h.

 

[175se]

Re: Overheating issue on a 1998 Johnson 115 hp

You can't lower that lower housing enough to do the repair. It's a matter of drilling holes in the cowling to use sockets and extensions, cutting the housing away and reinstalling it with plates and pop rivets or pulling the power head. The job is a b***h.

boobie is right it is a b***h, but it can be done with swivel sockets and good wrenches and patience, never had to cut a lower pan yet.

 

[Wheeler wheeler]

Re: Overheating issue on a 1998 Johnson 115 hp

Well guys I started out this am to replace the t.stat and decided to pull and replace the hoses from the t.stat to the cylinder head and flush the system with a strong stream of water into each side of the t.stat housing and each side of the cylinder heads.....when I got to the left side of the cylinder head I sprayed quite a bit of water in the head and as the water was flowing out I could see quite a lot of white particles coming out....I assume that this was mineral/salt build up.....I installed the new hoses and fired the motor up.....she ran cool for about 20 minutes....I shut her down and then started her again......she fired right off instantly....had a very strong pee stream.....I could place my hand on the cylinder head for several moments with out it getting hot at all..... I hope that the t.stats were stuck......maybe I am good to go....Thanks for everyone's input....you guy ROCK!