My kfx-400 will not stay running, i have changed my plug and still has a problem staying on at low rpm. It feels like it runs strong once its running and i am throttling it. But once it comes to idle it goes in out Reving fine and than idling so low it shuts off. I found a huge puddle of oil in my air box and dripping from my filter. Why would it be coughing up oil? Engine does not make a funny noises. PLEASE help i am planning a big trip in two weeks.

 

do you have nos on that thing. Nos is known to cause a lean condition even with added fuel jets. Too lean too long too bad. maybe the added cylinder presure pushed oil through the breather. Does a KFX have a crank breather vented to the airbox.

 

Sorry I don't have an answer but how do you like that nos set up? Iread about it in the magazine and sounded cool.

 

when u cleaned ur air filter u poured too much oil on it and now it cant breathe propperly. try taking the filter off and see if it runs better. if it does u need to squeeze all the excess oil out of the filter. i did the same thing and when i put my pipe on it wasnt allowing the air through. with the stocker it was okay, but not aftermarket.

 

Well i think i figured out why is was coughen oil, it does have a breather tube right in the snorkel tube from the carb. I may have added to much oil because i just changed my oil. But on to the bigger problem. Cam chain is slappen big time i think its strechted, i just brought it in and am going to have the engine spilt and new camchain put in. BIG $$$! I dont know why this could of happened its been getting louder. IT was happeing before i got the nos so dont blame it on that. Could it be because of the +1000 cdi. AS for the nos it runs nice! Its really FASSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSt . I raced my buds yfz-450 modded and beat him by a sick amount. I even gave him a 4 quad head start.