My 01 WR is making me nervous. It has a Z start and 03 YZ cam installed as well as most of the other TT mods. It just started stalling very easily when I stop and when I kick it over to restart, the kick starter rolls over much easier than before and kicks back hard, like a backfire with no bang. It still eventually starts but it seems like something is not right. It had a new top end last spring and had the valves rechecked probably about 10 hours ago. Any opinions are appreciated.