Any idea why my spark seems to be coming and going? The atv would not start so i pulled the plug to see if it is getting fuel and it was. I then held the plug against the block and no spark. I played with wires, tapped on the coil, tried another plug and other misc things. Still no spark. Then suddenly, the spark appeared. I don't know what to attribute it to, I think it just started sparking on its own. Obviously something is intermittent. Any ideas?

 

I would replace the plug cap.

 

Have since learned it is either the Stator or the CDI box, don't know which yet. The intermitent nature makes it harder to diagnose.

 

my old 300ex did this.

you'd be riding...it would shut off..no spark..smack around the 4-wheeler and it would start right up.

My wiring harness had a break in it somewhere, i just bought a new one. And in the process of smashing around my old wiring harness something arced and blew my CDI!