I have a 2003 KFX 400 and the motor has a hard time staying at one idle speed, It will periodically idle up then idle back down by itself, Also when your riding it and you let off of the gas and pull the clutch in it doesn't idle back down immediately it stay reving kinda high then it will eventually idle down. Any suggestions

 

definitely a vac leak.. check the carb boot. they tend to come loose on those things it seems..

make sure the airbox is tight and filter is clean..

all the vac lines in place and not cut/kinked?

doubt its a carb issue as far as float sticking or whatever.. it could be, but we'll rule out the simple and obvious stuff first, before we get into something that may cost money..lol

keep us posted bro!

 

Well I checked all of the lines that were on it for any inperfections and I also checked the boots that got to the carb. and everything was tight, I also cleaned the air filter and it still doing the same thing, Any more suggestions.

 

IMO, since all the lines tested good, etc, I would tear into the carb. Make sure you didn't suck any trash up, floats at right height and doesn't have a hole in it. Make sure jets are clean, etc. Make sure all the rubber components in the carb are good.

 

hmm, a float with a pin hole is easy enough to pinpoint. So what is the outcome from the above suggestions?