I have an 02 400ex, it has mods but I dont really know exactly what. I was told it had a 440 kit, jets and a few other things. It has DG exhaust. Anyways it doesn't run right, if you open it up it falls on its face, spits and sputters. Does this have something to do with the carb? If so should i rebuild the carb or buy a referbished one for $95? Also it burns oil pretty bad, piston rings? thanks matt

 

Hi, welcome to the forums.

Something that has always irritated me is that it seems every EX I have ever seen and most definitely one's I've went along with during a purchase am told has the "440 kit" and every used sports quad always has a "cam in it". Anyway, if it's been pipped you need to check to see if the carb was jetted properly. I always check. While your doing that I would give it a good cleaning too.