I have a 1987 Fourtrax 125 that has always ran great, but fouls the plug every few months. Usually, I just pop a new plug in and it fires right up. Today, I put the new plug in and there's no spark. Any suggestions?

 

is the quad burning oil or smoking? it could be you piston and/or rings

 

No, it doesn't burn oil, and doesn't smoke at all. I know it probably needs new rings, that's probably why it fouls plugs. I just can't figure out why the new plug isn't getting any spark.

 

well make sure the cap is on the plug lol ive done that before and make sure the cap dosent have a cut in the wires or anything ive done that also lol and im not sure just dont get rid of it its a honda it will run 4 eva! my old 87 250 utility was beating 99 big 400 4x4s through the mud!

 

Did you try a different plug after that episode with no spark? Or did you keep tinkerin with the
same one?? Sometimes you can get a faulty plug, could be a hairline crack in the porceline
or could be a void{a bare spot} in the glaze, or maybe the electrodes themselves are faulty.
Let us know.

 

Kill switch on? Gap too big on the plug? Battery discharged?
I agree with trying another plug, actually any plug will do for a spark test ( holding the plug against the head), that is known to work.