I have an 2000 400ex with a rebuild top end done bout a year ago now... Anyway I'm not a bike wiz lol... My problem is that my bike does not like to start off of the battary but if I bumb start the thin it works fine it idles fine I put a bran new plug in cause the one I had in er was a bit black but no where near done and it still does the same thin but tho it will start off of the battary (if the thin doesn't die tryin) and I have to play with the gas a lot to the bar then half to the bar again then no gas what so ever then it may do a LOUD back fire then if I jus hit the starter the bike will start

Thanks

 

My son has an LTZ400 that was doing the same thing. Turned out he needed his valves adjusted. After that, it ran like a brand new bike.

 

thanks for your help tekrsq...do u no if there is an valve adjuster if not ill
have to take it to the dealership

thank