starting my 400ex
 

i just got a 03 400ex and it won't start. any ideas?

Need some more details.... Does it turn over or do you get nothing at all? How long has it been sitting?

it started fine yesturday, i left the key on last night and had to charge the battery and now it will will crank but just doesn't want to fire. it acts like it isn't getting gas or something.

Have you checked the kill switch on the left side? I have lost count of the times I have cranked and cranked my quad only to find I had left the kill switch in the off position, turned it on and it fired right up. Thats why I only use the key to shut my quads off now.... hard to forget to shut off and pull a key when done riding...lol.

it could be fouled spark plug,bad coil,cdi box,stator,ect,start with a new spark plug and go from there