Johnson 120 looper no fire

cooldog4

Cadet
Joined
Apr 21, 2009
Messages
6
I have a 1990 120 Johnson VRO looper outboard that has a mind of its own. The thing has ghosts in it. When it has fire it runs and idles like a new one. But am having a intermitten problem with the fire. One time it will fire, then the next time no fire. Play around unplugging wiring plugs and trying different things, finally will fire again. Fires fine for the next few trips, then next trip no fire. This has happened several times now. I have no fire now, I have replaced the power pack still no fire, then replaced the stator still no fire, then replaced the timer base still no fire. The flywheel magnets are in good shape. So my question is what else is left in the iginition circuit that I haven't replaced? Can the regulator/rectifier cause a no fire condition? And thought about the wiring harness, but when I replaced the power pack, stator, and timer base I pretty much replaced the wiring, correct?
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: Johnson 120 looper no fire

Are you sure you have no spark at all? If so, try unplugging the red cannon plug on the wiring harness. Now check spark again. Don't try to start it because if it starts you'll have no way to shut it off without flooding it.
 

cooldog4

Cadet
Joined
Apr 21, 2009
Messages
6
Re: Johnson 120 looper no fire

I am sure I have no spark on all four coils. And the umbellical plug( red cannon plug) is unplugged. Also the black/ yellow stop circuit wire is unplugged.
 

mrod322

Cadet
Joined
Apr 13, 2009
Messages
19
Re: Johnson 120 looper no fire

i'm troubleshooting the same issue on my 1995 225. cant figure it out. I have change trigger,stator and now going thru the second Power pack. The only thing left is the wiring harness or the engine grounds....

This sucks...
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,931
Re: Johnson 120 looper no fire

I see this problem several times a year. Remove the spark plugs and test,if you have spark the starter is not spinning it fast enough.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: Johnson 120 looper no fire

it has to spin +-300 rpms to start.
 

jtcarter

Petty Officer 1st Class
Joined
Apr 26, 2008
Messages
226
Re: Johnson 120 looper no fire

I had a similar problem, turned out to be a bad battery. If you didn't get it cranked the first time around it wouldn't fire because it wouldn't turn it the neccessary 300 rpm.
 

cooldog4

Cadet
Joined
Apr 21, 2009
Messages
6
Re: Johnson 120 looper no fire

I have pulled all of the spark plugs out and put a battery charger on the battery while cranking it over. Still no fire. None, not even a faint weak spark. What about the diode in the wiring harness, anyone know where it is? Could it be bad and causing this?
 

mrod322

Cadet
Joined
Apr 13, 2009
Messages
19
Re: Johnson 120 looper no fire

Check your center hub magnet, it has a cover that if it turns it will cover the timming marks.
 
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