i guess i should start with spark plug then plug wire, coil, cdi and last the stator. but if anyone has other suggestions i would like to here them. my 14 year old son put new rings in it and gaskets, but did not tourqe properly and lost coolent then almost siezed the motor. i retightened everything and fixed problem but noticed a backfire every so often then started to loose spark on one side after 20 min of riding.