my aunt has this 400ex and it seems that the battery has been ran out i pushed started the bike and then the lights would come back on but when i turn the bike off the light goes off. is there anyway it can charge it self or a way i can rig something to charge the battery?

 

Guy, take your battery out of the holder so you can access the terminals and put it on a charger on 2 amps for maybe 5 hours or so. If it doesnt come back to life than it is probably dead for good.

Adam Smith

99 400EX

 

If you will need to replace your battery, I would suggest that you get a Yuasa # YT12A-BS
It fits as stock but it gives you 185cca instead of the 125cca of stock... I use it, this info was given to me by Jason at LRD Performance..
It is a must if you have a new cdi box.