COIL GONE BAD?

[JAMESEPARMLEY]

Ihave a 1972,20HP,Johnson.What are the signs of a coil gone bad?Went out fishing one night,engine ran great.Started up engine to head in,I noticed a power loss in my high speed throttle,let off on throttle engine would momentarily kick into high speed(accelerate),then spit and sputter and shake then back to trolling speed.So I thought I might have fouled a plug.Bought new plugs gapped them and installed them didn't fix problem.So I checked choke shutter valve to see if it was opening and closeing properly it was working.So I pulled flywheel to check timing and point gap and looked for loose or damaged wires everything looked alright.Fuel pump was working.So I'm down to a clogged carburater jet or bad coil.Will a engine start and run with just one good coil.How can I check coil without having to buy expensive Johnson analyzer equipment?Could gas can be clogged with rust or some kind of foreign matter?It starts ok and every once and a while in gear ,it will try to accelerate into high gear,then sputter and shake and back to trolling speed.If it was compression it wouldn't run in gear or start would it?Maybe a broken spark plug wire?Any suggestions or input would be greatly appreciated,THANX,I'm missing out on the sturgeon and striper winter run the STURGEON GENERAL.

 

[rodbolt]

Re: COIL GONE BAD?

beats me but at 25 a piece I would just replace them if they show any signs of cracking, also check/replace the points and condenser while your in it. fuel pump and carb kit is about 30 dollars and takes an hour or so to rebuild.<br />that engine will run on one cylinder so if you can load it and pull then replace the plug wires one at a time you can check which cyl is not fireing.

 

[Solittle]

Re: COIL GONE BAD?

See if you can determine which cyl is not firing. Then switch coils. If the problem follows the coil you have found the problem.<br /><br />Bite the bullet though and follow rodbolts advice.