59 Johnson Coil question

[deezelteck]

Hello All,
I have been working on my 35 Hp johnson and found that it seems to be running on one cylinder. The cylinder that I suspect is bad has spark but it is very poor and kinda intermittent. Is this usually the way that a coil goes bad? Also when the engine is running it will cough and pick up but then its back down to a rough idle, it even seems like it fires at the wrong time some times. I want to say the coil is bad but I have never seen one go bad. Thanks to all that helps.

 

[tashasdaddy]

Re: 59 Johnson Coil question

when were they last changed. they discolor, crack, have a burnt of darken spot on them.

 

[deezelteck]

Re: 59 Johnson Coil question

I don't know when the coils were last replaced, but they are not discolored, burnt, or cracked. Here is a picture.

 

[R.Johnson]

Re: 59 Johnson Coil question

Those coils do look good, but you can't always go by that. Ckeck the point contacts', clean if needed. Do a ohm's check on the coils, compare the working one again'st the suspected one, rough test, but use what ya got. Could be a consensor acting up. Check, and see if you have a spark plug lead going to ground under the mag. plate, not uncommon.

 

[tmcalavy]

Re: 59 Johnson Coil question

A bad coil on its way out will sometimes throw a good, hot spark when the motor is cold/warm but drop out after it attains operating temperature. Might also have a dodgy wire as the culprit.

 

[freddyray21]

Re: 59 Johnson Coil question

clean and re gap the points first. A bad condenser can also give you the problem you are having.