i got a 2001 400ex.i got it out one day i took it for a ride around my yard then tryed to start it a few days later and all it did was backfire like crazy and smoke so i thought it skipped timing so i took it apart and no skip in the timming no bent valves and the valve clearances were fine.also the timing chain was tight.so i went to electrical i put a new stator on it that didnt work so i put a new coil on it, nothing. then i got a new white brothers cdi box that didnt work. so i took the carb apart and the needle has a tiny flat spot on the tip tiny. so i droped the needle and nothing.i mean this thing back fires like crazy. it acks like it is off timing but its not. ive taken it to a shop to get fixed and no one can figure it out i even went to school for small engines. its such a shame it wont run if anyone can help me please give advise.

thanks dale

 

put a new plug in it.

 

[img]i/expressions/brokenheart.gif[/img]Yep like someone said,Plug,+Plug wire,+bypass the kill switch,+jump the key switch wires!!!!!It's som-thin Simple!!!!!!!!!!.Eddie.2 400ex's 1 250Suzuki sport Quad,1 2002 Blaster&240 kit,1 2005 Banshee&Bunch of STUFF.hard to keep these all running,Lot's of rider's but I am the only one that Wrenches on them.DANG Kids.Luck,U will get it.The 400ex is hard to beat!!!! There good machines.

 

its got a new plug and the coil and wire is new to but the kill switch is broken it just kinda jiggles around and stuu also the clutch leaver is new cause i broke the stock one and the wires that were suposed to got to it are just tied to gether could that have anything to do with it