Hi i am very frustrated because my yfz's idle stays idling high when i let off the gas and if i give it the gas quick again it goes back to normal idle... i do not know what to do ive tried a new vacume seal that sparks racing said to try an it still does it. please will someone help me with this. i dont believe its my throtle cable.. i have steel bradded throttle cable and ive tried new ones.. i dont trail ride this i only race it. thanks alot for your time its much appreciated.

These are some of the mods that might have something to do with it..idk
Streamline stainless hoses and cables,
Yoshi TRS TI- Tri-oval Exhaust,
Boyesen Quick shot 2 and power wing in carb,
Pro Designs filter system

~Frank

 

Welcome to the forum. Have you tried cleaning the carb? Maybe the float needle has crud in it. Usually that's accompanied with gas coming out of the overflow but, it's an idea. Other than that it sounds like a vacuum leak. Check around boot, maybe spray a lil' carb cleaner around it to see if you get a reaction.

 

I agree with Koopa. Check your intake tract for leaks causing a lean condition. Exhaust leaks can also cause a lean condition, but I haven't found them to also cause high idle.