HELP!!!!!! My friends atv died while it was idling, everything seems ok except it won't fire, but lights work as advertised etc....please give us a starting point to start troubleshooting, thanks for any helpful ideas!!

 

so theres no spark onthe plug or it wont fire meaning it won't start?

 

Talked with my bud today, the atv has weak spark, told him to try a new plug & let me know......kind of frustrating troubleshooting from 1500 miles away......