well, theres your problem!... but how do i fix it?

[Bigredgasbike]

my bike stopped running the other day, and i think i may have found the problem, when i tested the spark plug, it only sparks occasionally, instead of every time the engine spins. That would explain why it wont start, but what could be the cause? i tried two different ignition coils with the same results for both, which only leaves the magneto coil inside the engine.. can that even go bad?!? please help, ive got a donor coil if thats the problem, or i could just order another (if im waaay off and you think its something completely different, tell me)

 

[Mozenrath]

Yes, the magneto can go bad. I've heard that a jacked up CDI can short the magneto, wrecking it. But I've never had that happen to me so I'm not sure of the validity.

How did you test the spark plug?

 

[Bigredgasbike]

i set the base of it on the cylinder head, and cranked over the engine a few times

 

[GearNut]

Is your cylinder head painted? You want only bare, clean metal to rest the spark plug on. It could also be just a bad spark plug.

Try replacing it. It's easier and cheaper than replacing the Mag.

 

[inked1974]

other small thing to check is the ground wire to the mag.. i had a (what i thought) major issue. just a bad ground wire connect at the mag

 

[Drewd]

Another thing to consider doing: cut/remove the white wire at the base of the magneto....

 

[Bigredgasbike]

no, my cylinder head isnt painted, and i already tried replacing the plug, with no improvement