1974 25 hp johnson no fire

BGott

Recruit
Joined
Oct 2, 2011
Messages
3
Hi
I bought a clean electric start 1974 25 hp johnson yesterday for $100.00 that has no fire at either spark plug. It looks like it has 1 new coil, the points are gapped at .020 and look good. How do you check the coil under the flywheel (think it's called a driver coil)? Any thing else that I should check? I don't have the ignition switch wiring pluged in to the motor.
Thanks
Bob
 

milliesdad

Petty Officer 2nd Class
Joined
Dec 20, 2010
Messages
168
Re: 1974 25 hp johnson no fire

Unplug the kill switch leads and try it again. Use a real spark tester.

How do you know the points are gapped correctly?
 

BGott

Recruit
Joined
Oct 2, 2011
Messages
3
Re: 1974 25 hp johnson no fire

kill switch (ignition switch) is unhooked and I am using a spark tester. I don't know that the points are gapped correctly as I don't know what they are supposed to be gapped at, I know that both sets of points are gapped at .020 as I checked them with a feeler guage.
Thanks
Bob
 

milliesdad

Petty Officer 2nd Class
Joined
Dec 20, 2010
Messages
168
Re: 1974 25 hp johnson no fire

Next is to pull flywheel and check the coil.

Have you got a repair manual?
 

BGott

Recruit
Joined
Oct 2, 2011
Messages
3
Re: 1974 25 hp johnson no fire

Hi
I have the flywheel off. I think the driver coil under the flywheel is bad as everything else looks good. I don't have a manual for it. I was hoping that someone could tell me how to check the driver coil when I first posted. I have a snap-on voltmeter and have done a ohms check with the coil unhooked from both sets of points, from wire to wire reads 0.563 ohms if that helps.
Thanks again
Bob
 
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