Johnson 5HP Quiting

[magnum7269]

We took out this engine, and we started off from the dock and it ran real good for about 5-10 minutes then just died. So we trolled back and looked it over and tried starting it again, it ran and done about the same thing all over again. It acts like when it gets warm/hot something may be breaking down. The impeller is pumping water out, and the engine doesn't have a thermostat so it shouldn't be from overheating there. Any help or ideas is greatly appreciated, the model is a LD-10S from around 1965 I think.

 

[Rick.]

Re: Johnson 5HP Quiting

Next time it acts up do a spark check immediately. I have a strong suspicion you need to pull the carb. and clean it and install a kit. Take a good look at the Top Secret File at the top of this forum. Lots of good pointers in there. Best of luck. Keep us posted. Rick.

 

[film495]

Re: Johnson 5HP Quiting

Does it keep doing that if you prime the bulb every few seconds to make sure it is solid? Could be a fuel supply problem. If this works, could be a bum fuel pump.

 

[tashasdaddy]

Re: Johnson 5HP Quiting

i have the feeling a coil is failing.

 

[magnum7269]

Re: Johnson 5HP Quiting

Well, found out the problem was that water wasn't reaching the engine and it was overheating. So we got that part fixed, only problem now is we had the top off where the thermostat would go and it ran good (only let it run a few seconds to see if water was pumping, which it was). So resealed the top to the thermostat housing and tried to restart it and got nothing, not even an attempt to run. Tested it again with a compression tester, still had compression, check plugs, both fired good, and also was getting fuel to the plugs/cylinders (even put some premix in it to make sure). Now i'm totally confused on why it won't run or attempt to hit at all, unless it had to do with having the top off the thermostat for a few seconds and it done something to it. Thanks again guys for the help.

 

[Rick.]

Re: Johnson 5HP Quiting

"The impeller is pumping water out, and the engine doesn't have a thermostat"
These are your words from your first post. What changed? Rick.

 

[magnum7269]

Re: Johnson 5HP Quiting

Yea, the impeller was pumping water up in the leg and out the holes, but the water tube from the impeller to the engine wasn't hooked up in the rubber hose like it was supposed to be, so no water was getting to the engine to cool it. And for the thermostat from what i've read the 1965 did not come with a thermostat, but you could get the kit as an accessory.

 

[Rick.]

Re: Johnson 5HP Quiting

Thanks for clearing that up, I was confused. Try drying the plugs and then try starting it with the normal procedure. I can't see where you've done anything that would stop it from firing. Perhaps your plugs are too wet is all that comes to mind. What were the numbers when you rechecked compression? Are you checking compression with both plugs out? It could be a head gasket leaking water from the overheats into the cylinders. Do you see any water on the plugs? Good luck. Rick.

 

[freddyray21]

Re: Johnson 5HP Quiting

did you have the flywheel off perchance? If so unless you torqued the nut back down you have likely sheared a key and the timing is off. The key is what determines the time.

 

[tashasdaddy]

Re: Johnson 5HP Quiting

freddy, it would still spark but at wrong time, probably backfire.

 

[crxess]

Re: Johnson 5HP Quiting

Maybe water got under the flywheel. Let it sit for a day to dry out and give it a try.

 

[F_R]

Re: Johnson 5HP Quiting

Wait a minute...you said in your first post that you ran it till it quit, then got it going again and trolled back. And then you did it again. And again for however many times. Not meaning to be unkind or insulting, but you destroyed that motor, burned it up. I would have to see those compression numbers to believe it. Even in the remote possibility that it still has good pistons, you certainly burned the gaskets out of it and it is leaking water into the cylinders.

 

[magnum7269]

Re: Johnson 5HP Quiting

It might be that water seeped into the cylinders like you guys say, it has sat overnight to dry out some and we will probably work with it some today. And even though the engine ran hot and died those times, we let it cool down, found the water tube problem and fixed it. Then we started it back up, and water was pumping up to the engine. So we shut it down, put the thermostat cap back on and got nothing after that. I don't doubt it hurt the engine pretty bad, but if it ran after the cooling problem was fixed, I would think it would atleast hit a little unless like you guys say that water is getting into it. Thanks again guys for your replies.

 

[crxess]

Re: Johnson 5HP Quiting

Ahh.. just re-read everything.

I would suggest pulling the head and look at the gasket area. You may see where water is passing into the cylinders now that it is reaching the head.
As soon as you installed the thermostat plate, you boosted circulation around the cylinders.
Check the head to be sure it isn't warped. If it is, but not to much, you can true it on a flat surface with a piece of sandpaper taped down. work in a figure 8.