75 115 v4 random working spark cyl 1

[adam98]

1975 115 v4
cyl 1 sparks good now and again. at wot will some times only go to 4500 and slugish and other times flat out rips and screams past 5500+rpm. so i unpluged spark plug caps and ran one at a time to find cyl 1 spark plug looked like the odd one, and if i left cyl 1 spark plug cap off and ran motor and that was the problem and made no difference if plug cap on or left off.... checked spark while on the the lake and no spark as motor ran on 3 cyl and i tryed to ground plug. got home and now its firing fine.... My manual says i need a neon lamp tool to test coil and power pack.
Is it likely the coil to go out? or maybe power pack? Or do you recomend the flywheel to come off and is there anything to clean under there?

 

[adam98]

Re: 75 115 v4 random working spark cyl 1

So cyl 1 is sparking at the moment and tested everything the manual said I could test with a volt meter and all ok...
How much is a s80 or m80 neon test light or should I start rhrowinf parts at it. I'm guessing it's a coil or power pack... What's your thoughts? It works intermediatly at random rpm and times could go in and out could work fine all day or not all... Thanks again

 

[Daviet]

Re: 75 115 v4 random working spark cyl 1

Don't you have one coil per cylinder? Just swap #1 coil with another cylinder, if the problem moves you have found your problem, a bad coil.

 

[adam98]

Re: 75 115 v4 random working spark cyl 1

Just thought of that too.. swapped coil 1 and 3 charge from stator to power pack and still dead, swaped output from power pack to coils on power pack and THats it!!!! the coil works charge works but

bad power pack ..

So is this just a random failure or is it time for the power pack to die. any thoghts?

 

[boobie]

Re: 75 115 v4 random working spark cyl 1

Sounds like you got a bad power pack. No output to the coil.

 

[adam98]

Re: 75 115 v4 random working spark cyl 1

So im going to order a power pack. This site was a few bucks more. Im ok with that as i would support this site. but 2 weeks shipping? dont know if i can wait 10-14 days