86' johnson 120 idle/running problem

[evil grady]

The motor won't idle low, fast idle ok (missing)and is low on power.

If I pull number 3 plug wire off, the motor doesn't react at all. I'm sure its running on 3 out of 4 cylinders.

If I pull the plug, and start it, I can visually see a spark. The plug is always wet.

Inside the cylinder looks fine and I have 130 compression.

I rebuilt all the carbs, set floats, changed recirc valves, vac lines. fuel lines, new fuel pump. 4 coil packs, plugs, power pack.

Reeds look good.

need help bad!! Seems like ignition.. its dumping fuel out the exhaust..

 

[tashasdaddy]

Re: 86' johnson 120 idle/running problem

did you use a spark tester? or the old hold the plug to the engine test. spark should be blue and 7/16 jump. i'd recheck compression throttle at wot, if the same go to the carbs it's dumping fuel, float needles aren't sealing. just for starters. did you do a link and sinc, after the carbs.

 

[Walker]

Re: 86' johnson 120 idle/running problem

Do the spark test like Tashasdaddy outlined then Test it with an inductive timing light while running . Just because its firing from the high tension lead to the sparkplug doesn't mean the sparkplug is firing in the cylinder.
What plugs and what gap are you running??

 

[evil grady]

Re: 86' johnson 120 idle/running problem

They are QL78C??? (What ever the factory calls for)
The gap is .030

Everthing I did was through the manuel. I just check the sensor coil, all at 45ohms.

Carbs were sync'ed

 

[ezeke]

Re: 86' johnson 120 idle/running problem

You will be wanting to run on Champion QL77JC4 at abround .0325 AND making sure you are not using automotive spark plug wires.

Keep the temp wires away from your plug wires AND keep the wind at your back.

& BTW, Walker is the pro!

 

[evil grady]

Re: 86' johnson 120 idle/running problem

The motor always ran on the 78 @ .030 but..

I'll Be right back, I'm going to get some..

I'm totally stumped..

 

[evil grady]

Re: 86' johnson 120 idle/running problem

Ok, new Champion QL77JC4 @.0325 ,

same problem, dead # 3

any idea's?

 

[tashasdaddy]

Re: 86' johnson 120 idle/running problem

check the connection on # 3 coil you can even swap a coil out w /# 3. is it a new power pack or used.

 

[evil grady]

Re: 86' johnson 120 idle/running problem

4 new coil packs and one new power pack. I swapped it out with some old coil packs with the same results.

Can I swap the coil secondarys? Say, swapping 3 with 2 or something? Anything to try to move the problem to another cylinder.
I'm going to try to move the carbs around in the morning.

I'm feel like I took crazy pills!!:'(

 

[evil grady]

Re: 86' johnson 120 idle/running problem

What tells the cylinder to fire? The sensor coil? Timer base?
I did the sensor test, ohm'ed E against A,B,C,D and got 45 ohms each so, thats fine..

I don't know.........

 

[Walker]

Re: 86' johnson 120 idle/running problem

EG, Does your recirculation system have an inline check valve down on the bottom hose? It should allow flow one way only just like the recirculation valves.
Don't give up. Buy or Rig some kind of spark tester and do a spark test looking for spark to jump 7/16 of an inch like Tashasdaddy suggested. We have to determine if you're getting good strong spark to #3 and all cylinders for that matter.
I do suspect you have a fuel/flooding problem on #3 but we need to rule out a spark problem to be sure.

 

[evil grady]

Re: 86' johnson 120 idle/running problem

Is this a larger line/check valve, like a 3/8 size fuel line?

I'll have to look but, I changed every part of the system. I was very percise and check everything about 10 times.

Ok, I will go buy a spark tester first.

 

[evil grady]

Re: 86' johnson 120 idle/running problem

Update: I finished all the electronic trouble shooting in the manuel.

I bought a spark tester. The spark jumped 7/16 on all 4 cylinders.

I put checked all the gaps again on the new plugs Ezeke told me to get.

Turned the key and it runs like a top, nothing wrong what so ever...

If I pull plug wire 3 it goes back to bad, like it was before, so At least I know, it was only running on 3 cylinders.

?? I don't get it?? Other than changing the plugs and unconnecting and checking and re connecting things, nothing really changed. I tested 4-5 new plugs on that bad cylinder.

Its been idling for 45min with no real problems.

It does load up a bit but, clears out when I raise the idle, is that normal?

 

[Walker]

Re: 86' johnson 120 idle/running problem

. Just because its firing from the high tension lead to the sparkplug doesn't mean the sparkplug is firing in the cylinder.

Maybe the plug was bad. Happens sometimes

 

[evil grady]

Re: 86' johnson 120 idle/running problem

Walker,
I believe you. I never would have guessed, I can have 4-5 bad plugs or the difference between .030 and .032 can be the difference between running and not running..

Thanks everyone! I'll take it out on Sunday and see how it does.