1975 Johnson 115hp OB NOt spitting water

[bm9913]

I have a 1975 Johnson 115 OB. When I bought it and first started it up, after about 20 mins the warning horn started sounding. I replaced the water pump myself. And again after about 20 mins the warning horn sounded again. This time I noticed that the engine was spitting no water at all. I dropped the lower unit again and checked the tubes running from the water pump. As far as I can tell they both are clear and clean. Any suggestions? This thing is driving me crazy, although I am getting real good and dropping the lower unit. Thanks

 

[zachary00]

Re: 1975 Johnson 115hp OB NOt spitting water

I am having similar trouble, but have not become as advanced at you. I am having trouble getting the lower unit off. I have it seperated, but cant seem to find the where to disconnect each of the rods. Since you have become so good, I thought maybe you could share your wisdom. Hope you get it figured out.

 

[bm9913]

Re: 1975 Johnson 115hp OB NOt spitting water

The first time was awful for me. If your talking about the shift rod, I only have one. The disconect for mine is under the carberator. There is a large bolt that holds the two arms together that come from the shift cables. Loosen that one, you dont need to take it all the way out. You will probably need a swivel socket, it helped me alot. After several turns you can take a screwdriver and slightly pry the two arms apart and it the bolt is lose enough the rod will come lose. Im not the best person to describe this and I dont know any of the tec terms for any of it. Hope I was some help, if this isnt what your talking about let me know.

 

[TD_Maker]

Re: 1975 Johnson 115hp OB NOt spitting water

BM,
Sure sounds like a thermostat problem to me. They are not the easiest things in the world to get out and replace, but I think it will do the trick for you.

Zach,
I assume you have removed all the bolts (did you get the one under the trim plate?) from the lower unit. Did you disconnect the shift rod UNDER the carbs? This rod runs from this point down to the lower unit itself. You will see a screw that runs through the shift rod hole. Back out the screw, and the the lower unit should now just release. Not hard once you know the trick.

 

[bm9913]

Re: 1975 Johnson 115hp OB NOt spitting water

Thanks TD, where is the thermostat located? I have ordered a manual, but it isnt in yet.

 

[iwombat]

Re: 1975 Johnson 115hp OB NOt spitting water

Follow the big water hoses that come off the heads down to a cover on the front of the adaptor plate. The vernatherm (you have one vernatherm not two thermostats like later models) is under there. There's a 1/2" bakeolite spacer under the top cover that houses the vernatherm and the poppet valve - be careful not to crack it.

 

[bm9913]

Re: 1975 Johnson 115hp OB NOt spitting water

Thanks wombat, i found where it is, this wed Ill be looking into it, ill let you all know what I find out. Thanks again

 

[CARDNAL98]

Re: 1975 Johnson 115hp OB NOt spitting water

Before You Spend $40.00 On New Pop Valve Put It In Small Pot With Water And Put It On Stove And Let Water Come To Very Hot Boil That Will Free It Up. You Will See That When It Frees Up The The Needle In The Senter Will Slide Very Easy. The Hole Part Is About The Size Of A Five Sent Pease In Back Of The T Block Where The 2 Water Lines Conect Hope This Will Help That Is How I Fixed Mine Without Spending Big Bucks