ATV Carb Cleaning Idling Problems

What happens if you have idling problems after cleaning the carb on an ATV? Two of our viewers had questions about idling problems with their Honda and Yamaha ATVs, respectively, during our Live Q&A.

Our resident ATV pro John Talley livestreams on our YouTube channel every Friday at 3pm, and in this edition, John answers a couple of questions about idling problems with Honda and Yamaha ATVs after carb cleaning.

ATV carburetor problems

Honda ATV Idling Problems After Carb Cleaning

After cleaning the carb and jets on my 07 Honda 400EX, it now idles very high. I’ve adjusted the needle and checked the jets but I can’t figure out why it’s running so high. Any thoughts?

John Talley: Alright, well here’s an odd one. You may have all that set correctly but are you absolutely sure that you routed your throttle cable correctly and is it all the way down into the holder? Because I’ve put them back together where that cable got pulled up just a little bit and it was holding the main jet open a little bit. So make sure that it’s allowing it to close all the way. And make sure your idle screw hasn’t accidentally been turned in too far. But I’m sure you already looked at that so look at your cable and make sure that it’s not pulling that main jet or main needle up by accident. 

Watch the video above to see how to clean the carburetor of a Honda TRX400 ATV.

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Yamaha ATV Idling Problems After Carb Cleaning

I have a problem with my Yamaha YFZ450 2006 quad. On idle, if I add gas the RPM jumps to mid-range and stays there for few seconds. I cleaned the carb, but no success. Any thoughts?

John Talley: I know the YFZ450 really well but the machine I’m so familiar with is the fuel injection model, which started in 2009. So I’m not super educated on the carburetor that’s on there, but typically when I had a carburetor that was a vacuum type slide, which I think yours may be, if that vacuum slide is worn down, it’ll actually hang up and it won’t bring the needle back down to bring your RPMs back down. So I would take a look at the slide on it, especially if it’s a vacuum type to see if that’s holding it up.   

Watch the video above to learn more about whether to clean, repair or replace a carburetor.

Want to see more live repair questions answered? See more motorcycle and ATV repair questions answered here.  



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