thx. The plugs have been swapped around as have the new cdi's. Still no joy. The plugs seem to be sparking coz when the piston isn't firing and you pull the lead off the plug u get a shock. This problem only occurs after riding because when u leave it to stand for a weekend and start up but don't ride it doesn't happen. the ht lead from the front plug eas put on the back one and i had no problem.