1983 Johnson 15 hp stopped while running.

[fishimpaler]

Bought this motor used, took it out a few times, always started first or second pull, then, today , it died while running, and now refuses to start
Checked fuel for water, and it looks fine,

of note: We had been running it dry when done, but I've read that that might not be the best idea, and by running dry, i mean un clipping the gas line, not running out of water.

Any suggestions as to the next step?

thanks !

 

[Haffiman]

Re: 1983 Johnson 15 hp stopped while running.

Start by checking for spark and compression.

 

[fishimpaler]

Re: 1983 Johnson 15 hp stopped while running.

It started first pull just now, any ideas as to the cause of it not starting earlier?
tried all the adjustments, gave it 100 + pulls, no dice,
also, shifting has occasionally been problematic.

pumped some fuel into a jar, it looked fine.

any help appreciated, thanks !

 

[Haffiman]

Re: 1983 Johnson 15 hp stopped while running.

Next time it happens, check for spark. If no spark, disconnect the black/yellow cable into power pack. It might be an erratic stop contact.

 

[OptsyEagle]

Re: 1983 Johnson 15 hp stopped while running.

The other thing to do quickly if you can is to pump the primer bulb as it is starting to die and see if that revives it. If it does, it usually indicates a fuel pumping problem that will isolate it to a few things. The next test is to try to re-choke it just before it dies, if this gives any temporary help then look towards your carburetor.

Need more information to help narrow it down.

 

[BillP]

Re: 1983 Johnson 15 hp stopped while running.

Fuel connector loose? Gas can vent open?

 

[fishimpaler]

Re: 1983 Johnson 15 hp stopped while running.

I think it may be a timing issue?
i'm not completely sure as to how these motors work, but i think that timing is associated with the shifter?

It periodically (before pulling) becomes difficult to shift , especially into drive.











thanks

 

[OptsyEagle]

Re: 1983 Johnson 15 hp stopped while running.

I think it may be a timing issue?
i'm not completely sure as to how these motors work, but i think that timing is associated with the shifter?

It periodically (before pulling) becomes difficult to shift , especially into drive.

thanks

That's unlikely to be it. Timing would need to be off quite a bit to do more then cause power and perhaps idling problems. Usually when the motor is difficult to shift you just need to move the flywheel a little and line up the gears a little better. Pulling the rope a little does the same thing or manually moving the propeller.

My best guess, is that you have a fuel starvation problem, but this can be verified by the two tests I suggested above.

 

[fishimpaler]

Re: 1983 Johnson 15 hp stopped while running.

Alright, ran it a bunch in a tank, can't get it to die again, any ideas?

 

[OptsyEagle]

Re: 1983 Johnson 15 hp stopped while running.

Possibly an air leak that temporarily got fixed. I had an issue with my 9.9Hp that when I took it out in the cool morning, I never had a problem. When I took it out in the hot afternoon, my motor would die within 50 feet of my dock. Of course, priming the bulb gave it a temporary fix. The problem was my fuel hose with the primer bulb. I suspect the check valves were malfunctioning when it got hot. Anyway, changed the hose and the problem went away, but as I said, I had many runs where that hose caused no problems at all.

Perhaps your tank vent was not open when you had your problem. All kinds of answers. I still bet that if you have a problem in the future, you could "manually" pump the fuel you need to get home, by just priming the bulb every 10 seconds or so.

But I could be wrong.

 

[OptsyEagle]

Re: 1983 Johnson 15 hp stopped while running.

The other thought as to why it didn't fail in the tank is how long did you let it run in the tank? You see, if you are having a fuel pumping problem, what is happening is you are manually fixing up your carb bowl when you prime the bulb. When you run the motor, your fuel pump is supposed to keep filling the bowl. If your motor is not pumping fuel, the motor will keep running until the gas in your carb empties. At idle that can be 4 or 5 minutes. At wide open throttle, like I like to do when I take off from my dock, it will last about 30 seconds.

Anyways, fuel pumping failure is caused by either a defective fuel pump, fuel hose, fuel tank or an air leak in the fuel system.

 

[fishimpaler]

Re: 1983 Johnson 15 hp stopped while running.

ran it for 20 minutes +, then pulled hose and ran the carb down, hmm, in retrospect, when it died, it was a lot more abrupt then when running it dry.