yep, checked it, it has a new head, found out the new heads do use the larger plug. Thanks! that question is now answered. Will play with AP settings next. txfly, you mentioned a o-ring to pull the AP. Did you install it between the AP fork and the AP arm?
Just picked up a 2002 KTM MXC 400 and went completely through it over the past two days. Everything is turning out well except for some of the throttle responses. When twisting the throttle fast the bike sputters and wants to die, if you rev it slowly it works fine though. We went through the carb, the acceleration pump was dirty so we cleaned it along with the rest of the carb and put new gas in. There is something strange about the bike though, we were told that the motor was rebuilt in 2003. When buying a spark plug the one recomended at the KTM dealership and in the manual is too small. I am wondering if they converted the engine to a 453 and we might need to re-jet it. Any advice?