Starting 1979 Johnson 55hp

[Steve73]

Hi All,
I am still having a bit of trouble starting my outboard. It runs good when warm but seems to stumble and stall up to 10 times before it is warm and then starts to purr.
At the first attempt it will fire up great...run for 5 seconds then stall...the next few starts are very brief with it firing maybe 1 or 2 seconds until it seems to warm enough until it holds.

I know 2 strokes take a bit to warm up, but I would not think this is normal for the outboard to do this?

I have correctly gapped, and installed the correct Champion plugs as per the service manual. Spark is good on the 7/16 spark tester. Choke/solenoid is working good.

My start up procedure is a s follows:
1)squeeze primer bulb till its firm. 2) Lift warm up lever. 3)Turn key to start and also push in to activate choke. At this point the motor fires up easily, starts to run about 5 seconds but then fades out quickly and stalls. I then have to start it up to 10 times (with and without choke) until it seems to warm up enough, then the motor runs great when its warm.

I have also tried to activate the choke as it starts to stumble after running for a few seconds but with no success.

Thanks and any tips would be appreciated!
Steve

 

[Chinewalker]

Re: Starting 1979 Johnson 55hp

Do you continue to hold the choke in once it starts? You may have to toggle it seveal times to keep it going once it starts.

Also, verify that the choke is actually working. Take the cowling off and watch the choke solenoid when you push the key in. I had the spring linkage come undone on my 75 this summer - drove me nuts until I discovered it...

 

[Steve73]

Re: Starting 1979 Johnson 55hp

Thanks for the info! Choke is definitely working as I did have the cowling off......when the motor does finally start and hold idle, there is a lot of smoke almost like it may have been flooded. Could flooding be possible? Interesting thing is last year it only needed to be choked once and it would warm up with minimal effort.

 

[mark1961]

Re: Starting 1979 Johnson 55hp

Sounds like its overfuelling to me, hence the excessive smoke.....when you checked the choke operation did you actually eyeball the choke plates and ensure they return to fully open? There should also be a manual choke lever on the top carb, maybe you've knocked it while tinkering and not realised.....check that its in the off (open) position. If that all checks out my next thought would be a stuck open needle or a faulty float in one of the carbs.....how long since you overhauled them?

 

[Steve73]

Re: Starting 1979 Johnson 55hp

The carbs were overhauled last year along with a complete rebuild of the block. My choke is working 100%. It opens fully when not engaged, and the solenoid pulls it closed just fine.
I was out in the boat again today, interestingly what also happens is when I start the motor with the warm up lever up. It will run good for up to 30 seconds...then struggle and stall (even with feathering the choke). The same thing happened also at 1/2 throttle. Seems it doesn't like a consistent rpm during the warm up period.
Thanks for any info you guys may be able to pass on to me. I love this motor and when I figure this out will be very happy. The odd thing about it all, is it would start and warm up no problem last year. A quick initial choke and she was ready to go.

 

[mark1961]

Re: Starting 1979 Johnson 55hp

Is the stumbling and stalling accompanied by excessive smoke?

An overhaul on the carbs last year wouldnt necessarily rule out a stuck needle or faulty float......

 

[Steve73]

Re: Starting 1979 Johnson 55hp

Thanks so much for the info. There is excessive smoke. Is there an easy way to check the needle and float on the carb? Or does the whole carb have to be removed? Thanks again.

 

[Chinewalker]

Re: Starting 1979 Johnson 55hp

Gotta pull the carbs...

 

[mark1961]

Re: Starting 1979 Johnson 55hp

How firm does the primer bulb get when you pump it up?......it should reach a point where it gets quite firm (floats raised/needles closed in both chambers) and stays that way for a few minutes without running the engine......if it wont do this something is not right in one or both of the float chambers.

 

[Steve73]

Re: Starting 1979 Johnson 55hp

That makes a lot of sense. However, I tried that tonight and the bulb was still firm even after letting it sit for an hour. Do you think it could be something else carb related or could a timing issue give some issues only at start up?

 

[mark1961]

Re: Starting 1979 Johnson 55hp

Lets backtrack a little.....when pumping the bulb is there a gradual increase in its firmness to point where you think it need not be pumped anymore OR just a sensation that the bulb itself full of fuel with no increase in firmness beyond that?

Have you tried firing it up with a minimum amount of choke application?

Was a link and sync performed after the previous carb overhaul? Setting the timing would have been part of that procedure.....check the spark advance linkage for broken or worn connectors.

 

[Steve73]

Re: Starting 1979 Johnson 55hp

The bulb was pumped so it was full of fuel and could not accept any more.
I did try with no choke and very little choke but it had a tough time to fire up......seems I need the choke to get going but it over fuels.
Is the spark advance linkage located under the flywheel?
Thanks for all your help!

 

[mark1961]

Re: Starting 1979 Johnson 55hp

Is the spark advance linkage located under the flywheel?
Thanks for all your help!

Yes on the starboard side under the flywheel.....small linkage maybe 3 inches or so in length with plastic connectors on each end.

 

[Steve73]

Re: Starting 1979 Johnson 55hp

All linkages good......Had the boat out again today and I managed to keep it from stalling at start up by initially lifting the warm up lever...letting it run for 10 secs (before it would stall out) drop the lever down quickly and advance the throttle.....I slowly increased the throttle until the motor warmed up and all was running good.
You are right it does seem like its flooding with just the warm up lever engaged....However, could the idle speed setting be a problem with this scenario? Mind you once warm, it holds a steady idle at the current setting, and the idle set screw is set to the maximum setting. Thanks, Steve

 

[TrickyRicky]

Re: Starting 1979 Johnson 55hp

When you say idle set screw are you referring to the flat blade screw on the linkage? I so that setting is used to set the base timing to 4 degrees at idle. If that is all the way in then I would try this. Remove the 2 fuel bowl screws and drain the carbs Tilt the engine up. Try it a couple times and maybe pump the primer bulb to clear any water drops. Then button it back up and try to start it.. If that doesnt help I can list Lync and Sync since I just rebuilt my engine and have experience with that model.

 

[Steve73]

Re: Starting 1979 Johnson 55hp

Thanks for the reply. Are you thinking there is moisture in the float bowl? Also, when the idle set screw is adjusted, do you need to check the timing?