1979 75 hp Johnson bogging - now won't start

Ski Baby

Recruit
Joined
Aug 17, 2011
Messages
1
Hello,
I bought a 1979 Johnson 75 hp a month ago and the owner stated he had not driven it but had started it every spring and fall to keep it operational for the last two years. He said he ran Stabil in it religiously every tank. It ran fine for the first 3/4 tank (using his tank of gas which looked/smelled ok . . . I know now, BAD IDEA) and then started cutting off at idle, when put in gear, and during accelleration. It started cutting off at idle and would start right back up. It also would cut off after putting it in forward or reverse but would start back up right away. I had to really finess it to go into forward and accellerate without it cutting off. Once I got it to go, it ran great. I purchased some fuel additive/cleaner at Auto Zone made for marine engines and added it to the tank when I refilled it to full and also added Stabil. It started after a few trys and we were off to fish at high speed a few miles away. When I started it to move our location, it took several attempts and the (can't think of the name . . the small throttle used in neutral) had sluggish results. It was hit and miss to get it going. On the way home, we were planed out and very suddenly it cut off at high speed like I had turned off the key. It started up right away with no problem and gave no problems during accelleration. This happened four times on the way back in ruff and smooth water. I thought it could be the fuel tank with foreign debris in it, so I changed out the tank for another that I had filled to full from an original 1/4 tank old gas (yeah, bad idea). I had added fresh gas to the old and put in the additive and Stabil. The engine would no longer start and we got towed in. I checked the fuel filter and it was perfectly clean. I opened the fuel pump and it was clean. I am replacing the fuel pump because I dropped one of the tiny pieces under the engine down into the hollow cavity. Any thoughts on what it could be? I doubt it is the fuel pump. And yes, I am feeling really good about costing myself $ for the fuel pump! You all are great for helping us no knowledge folks - Thank you!

P.S. What are "Tags" when you post a thread? What does "Post a poll" mean when posting a thread?
 

calboats

Seaman Apprentice
Joined
Jun 6, 2009
Messages
41
Re: 1979 75 hp Johnson bogging - now won't start

Check the plugs, electrode colors, wetness, gaps, and how long they have been in the motor. I have also been guilty of not looking at them often enough, or after changing to high lakes altitude. The higer altitude created gunk on the plugs from the richer mix can really foul the plugs on the next trip at sea level. Yep, first fuel, then hoses, plugs, and maybe a check on spark strength just in case.

I overheated once, and that happened sort of like you say -- finally got the head trued flat, and now no problems -- well, that kind anyhow.

Good Luck, Cal
 
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