35 Johnson,bad spark?

[MMHagler]

My problem is when it starts it sputters and coughs and tries to quit. When I pulled the bottom plug wire off it runs well but on one cylinder. Also when I did get it to move if I gave it half throttle or better the sputtering and coughing stopped and it ran fine on 2,thats good except for trolling. Any ideas what it could be. Write slow because I am no mechanic. I just bought this 35 Johnson,don't know the year but it has an orange stripe on top and a grey one on the bottom with 35 Johnson written on it. Thx for your time

 

[bouttime007]

Re: 35 Johnson,bad spark?

Look for a model number on a plate near the mount bracket, with the model # you can nail down the year.

 

[bonz_d]

Re: 35 Johnson,bad spark?

Welcome aboard MM,

From your discription of the paint scheme it sounds like a late 70's model. As for your problem it sounds as though you have a dirty or misadjusted low speed idle circuit in the carb. That carb only has one adjustable needle valve screw and that is for the low speed idle. The high speed jet is "fixed" and canot be adjusted. How did it run or how does it run if you try removing the top plug wire?

 

[MMHagler]

Re: 35 Johnson,bad spark?

Thats how I found out it was the bottom plug. There is a screw in the center thats says richer/leaner is that the jet your talking about? It has Start at 1 1/4 written on the airbox or whatever is screwed too the front of the carb. Thx

 

[bonz_d]

Re: 35 Johnson,bad spark?

Yes that screw would be the low speed idle adjustment.
Are you getting a good spark to that bottom plug? A spark tester is the best tool to use to check. Can be had at any auto parts store pretty cheap.

If worst comes to worst rebuild in those carbs is very simple and doesn't take alot of time. They are very simply designed with few moving, removable parts and the biggest hardest part is to assure that everything is really clean.

 

[MMHagler]

Re: 35 Johnson,bad spark?

Yes that screw would be the low speed idle adjustment.
Are you getting a good spark to that bottom plug? A spark tester is the best tool to use to check. Can be had at any auto parts store pretty cheap.

If worst comes to worst rebuild in those carbs is very simple and doesn't take alot of time. They are very simply designed with few moving, removable parts and the biggest hardest part is to assure that everything is really clean.

Could it just be the bottom coil? When I get it going down the river with the motor rev'd up at about half to full throttle it seems to work fine.

 

[bonz_d]

Re: 35 Johnson,bad spark?

Could be a coil cutting in and out but to me it sounds more like a fuel problem. The low speed jet is very small and doesn't tae much to block it up and that it smooths out above idle would also suggest fuel. Try pulling the plug under load and see if it cuts out, then try the top plug. See if it reacts the same way.

At start up does it sound like it's idling too slow? There is another adjustment screw on the side of the motor where the remote control connects. This is a plastic screw and does have a tendancy of braking off the tip.

On the transom clamp there should be a tag with the model and serial number on it. Get the model number and I will tell you waht year this is. 1977 and below useed points,1978 and above used electronics along with a stator that will charge a battery on electric start models.

 

[MMHagler]

Re: 35 Johnson,bad spark?

If I take the low speed jet completely out and try and start it should gas come out of that hole because thats what I did and nothing came out,does that mean its plugged? Put a different coil on and it did the same thing,pulled it off the bottom plug and it ran good but on one,same as before.

 

[flintcreek]

Re: 35 Johnson,bad spark?

No if you take the low speed needle out, no fuel mix will come out. These carbs are not hard to rebuild at all. I would recomend a manual if you want to work on it your self. Some time you can check one out at the library.

Flintcreek

 

[bonz_d]

Re: 35 Johnson,bad spark?

MM, you didn't say as to whether you pulled both plugs, one at a time to see if there is a dead cylinder. Which is why you also need to pull and check the other cylinder while it's running. A spark tester would still be a good investment.

Also agree that the carb should be pulled and cleaned. These carbs are very basic. A float and needle and one mixture screw. That's all that's inside it that can be removed. If this is an electric start it is actually more time consumeing removing the carb than actually rebuilding it. Again the low speed circuit has very small passages and can be easily blocked by dirt and varnish.

 

[MMHagler]

Re: 35 Johnson,bad spark?

The carb is off and being cleaned with new parts. I will flush the gas tanks and start over. I switched the coil and it did the same thing. The carb is a real pain to get off with the starter stuck beside it and it looks like half the motor has to be taken apart to get the starter off so you can get a wrench in there to tighten the nut,nice design. If this doesn't work what is the next thing to look at. I believe its a 76 from what I have read. Thx for your time

 

[bonz_d]

Re: 35 Johnson,bad spark?

Yes the hardest part is getting it off! Now that you have it off the two suggestions that I have are to get a couple cans of spray carb cleaner and a couple cans of canned air. Use the 1st can to clean the body as good as you can then use the second can with the straw and spray it through all the passageways until you can see a good spray coming out another hole. May need to find a small wire like a stripped bread tie to poke into the holes also. Just be careful not to break off the wire! In between spraying the cleaner be sure to blow it out well with the canned air.

Good luck and let us know how it turns out!

 

[MMHagler]

Re: 35 Johnson,bad spark?

Had the carb cleaned,flushed the tank and it is running better but still has the cough and sputter at low speed. The guy that cleaned the carb set the low speed at about 2 1/2 turns but the airbox says 1 1/4. Could this be part of the problem and should I leave it at 2 1/2