06 yz450f idle issue

5 replies to this topic
  • seacraft69

Posted February 22, 2014 - 02:01 PM


Hello. New member here. I bought a 06 yz450f on monday and finally got to ride it today. It runs really good everywhere except it wouldn't idle. So I turned the idle adjustment screw in and brought the idle up, but when I did I noticed gas started coming out one of the vent lines. So I screwed it out slowly and the idle got slower and so did the gas flow. I finally got it where no gas was coming out the vent but the ldle is very low. Any ideas? And thanks for replies

  • grayracer513

Posted February 22, 2014 - 07:38 PM


The only thing that makes sense to me is that the float needle isn't sealing well, and the pitch of vibration at a higher idle speed is causing the float to bounce around enough that it leaks a bit, then floods. 

  • seacraft69

Posted February 22, 2014 - 08:13 PM


That makes sense except for the fact that when I barely touch the throttle it will sit and run at about what the idle speed should be and no gas is coming out the vent line. Could it because of the po adding an fmf 4.1? He said the bike is stock except for the pipe and a 51 tooth sprocket.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • Will.A.R.

Posted February 23, 2014 - 06:09 AM


+1 on gray. Check the valve. I've had that happen more than once.

  • grayracer513

Posted February 23, 2014 - 08:10 AM


Could it because of the po adding an fmf 4.1?



  • seacraft69

Posted February 24, 2014 - 09:52 AM


Ok ill check it out. The po gave me a carb rebuild kit that looks about half there. I'll check when I get home to see if the float needle is in there. And thanks for the responses.

Related Content


Chubby dad, looking at bikes , First trip to the orange/black forum ! by Slow_ride

Dirt Bike   Make / Model Specific   KTM   250-530 EXC/MXC/SXC/XC-W/XCR-W (4-Strokes)
  • Hot  28 replies

Michigan Motocross Tires by 288yz450

Dirt Bike   Dirt Bike Regional Discussion   North
  • 1 reply

BIGBORE FOR YZ450F 2006? by Taattie94

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 1 reply

Megabomb Fitment by 288yz450

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 1 reply

Yamaha YZ450F 2017 by Chris.GVS

Yamaha YZ450F 2017
  • * * * * *
  • 1 review
  • Last review by Tommyk_55
  • On January 15, 2017

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.