Need help...1 spark plug no firing

[Warrior04]

Has anyone run into the issue with the no.1 spark plug on the oil tank side not firing consistenly in a 2004 Warrior Rx? I pull the plug and its like its never been used. I've changed the coils over between cylinders to eliminate that as the fault as well as spark plugs. I have tested the resistance from the Cdi box wire to the plug wire and it seems to be good (no grounding). Could this be a Cdi box starting go?

Update - disconnected the cdi, heated it up to get all moisture out and re-connected. Checked and had spark while turning the engine over, re-installed on the plug and went for a short ride to get to operating temp. Upon return check spark again and no spark.

 

[Warrior04]

Finally figured it out, coming off the Cdi box is a ground block that has six ground wires all connected by a six pronged connector. This connector was slightly corroded, cleaned it up and now the sled runs like new.

 

[superfan75]

That's awesome that it turned out to be something simple !!