400ex wont start!! need help

Alright my 2001 400ex has been sitting in my garage for about a year now. Im looking to sell it so I want to get it up and running. I changed the oil and oil filter, drained the old gas out of it, changed the spark plug and put a new airfilter in it. after all this the only way i can get it started is by jumpstarting it. I had it running for atleast 15 minutes and everything was fine. when i shut it down and left it for a little while, i tried the electric start and it sounds like wants to start but it just wont kick over.....

I cant figure it out any ideas  

any help is much appreciated!! thanks  

the battery could have a dead cell, meaning it just wont have enough cranking amps to turn it over.
or turn it over but just not fast enough.

have you tried charging the battery? or a new battery?  
Keep it RUBBER SIDE DOWN!!

yeah i was thinking it could be the battery, i charged it over night and it was still the same thing this morning. I jump started it and rode it for a half hour today....would that have charged up the batter enough?? it seems like it has enough power from the battery but im probably wrong lol  

the charging system is a trickle charging system.
so it's not likely it charged it much if it was pretty dead.

it does sound like either the battery has a dead cell.
(it'll run fine if you boost it if it has a dead cell,) or the starter is dragging.
also check all of the connections  
Keep it RUBBER SIDE DOWN!!

Put a new battery in it today, still wont start...idk im lost  

but it will start if you boost with another battery or boost box?

it's just possible that you have a short somewhere.

trace down all of the wires and make sure they are all well connected and tight.  
Keep it RUBBER SIDE DOWN!!

i checked all the wires everything looks good. the way i was jump starting it was towing it behind my truck lol but it was running fine. i checked the sparkplug and it spelt like gas and there apppears to be a small amount of gas coming down the air intake from the carb.....maybe ive just been flooding it while trying to start it...how long should i wait before trying it again??  

it sounds like it wants to start but just might be flooded  

i have a 2002 400ex and i just put a 440ex kit in it and its in time but it wou't start any ideas  

put a new spark pluf in it, you may have fouled it out, and try cleaning the carb.  the pilot jet could be clogged.


440ex:  check the valves. you may have one bent or burned  
Keep it RUBBER SIDE DOWN!!

I was reading about a starting issue at http://www.atvwheelin.comthat might help!