Quantcast
Jump to content

  • Do you own an ATV? Join our Forum!

    As a member, you can post in our forums, upload your photos and videos, use and contribute to our downloads, create your own member page, add your ATV events, and even start your own ATV club to host your own club forum and gallery.  Registration is fast and you can even login with social network accounts to sync your profiles and content.

James Lecy

2007 Yamaha yfz450 Idle Issue

Recommended Posts

Doesnt want to idle unless choke is on and then it really high. Back fires constantly. Installed bigger jet because plug was really light. Could it be Timmy or bad carburetor?  Yamaha guru's help me out.

 

Share this post


Link to post
Share on other sites


Do you have a factory exhaust or aftermarket? 

* Added to the topic title -  your issue and manufacturer. 😁

Share this post


Link to post
Share on other sites
12 hours ago, James Lecy said:

Doesnt want to idle unless choke is on and then it really high. Back fires constantly. Installed bigger jet because plug was really light. Could it be Timmy or bad carburetor?  Yamaha guru's help me out.

 

It sounds like you have a low speed jet clogged up.  When the choke is used to keep a motor running it generally leads to the low speed idle circuit being stopped up in the carburetor.

  • Like 1

Share this post


Link to post
Share on other sites

I've had pretty much this same issue on my 2003 Kodiak 450 for years.  It's really annoying when plowing snow given all the start-stopping-stalling.  At times I've used the choke slightly engaged to keep it running, but I know that's a band-aid fix.  I've tried messing with the idle speed, but that didn't really work.

Which jet is the low speed one?

Share this post


Link to post
Share on other sites


The carburetor would have to be removed from motor.  The carburetor would have to be disassembled soaked in a carburetor cleaner and the jets cleaned out. Air blowed through the passages in the carburetor. New parts added if needed and the carburetor reassembled and reinstalled on the motor. Repair manuals for that year, make and model should have pictures and written information on carburetor removal and repair.

Share this post


Link to post
Share on other sites
21 hours ago, James Lecy said:

Doesnt want to idle unless choke is on and then it really high. Back fires constantly. Installed bigger jet because plug was really light. Could it be Timmy or bad carburetor?  Yamaha guru's help me out.

 

Have you checked the valve adjustment . My 2008 did the same thing when I bought it brand new. Brought it back . The said it was old gas . Same problem . Would only start with choke on  even when warmed up . It would idle then back fire and stall. Adjusted valves . (To tight ) . Don’t need choke to start and idles fine . Worth checking .  

  • Like 1

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Similar Topics

    • By Nick Gudex
      Hello I am new to this site and I havea problem. I have a 1987 big bear 4x4 that will not spark. I tested pick up coil per repair manual and I tested my new coil both ok. It puts out 9 volts at the coil but It is reversed polarity. So when I hook my meter up to it she shows -9 volts while cranking. When I put a test light  on it it flashes. Being an electric system this should tell me something but I don't know what its telling me. I have yet to meet one i could not fix but this old girl has me stumped. Any help would be awesome. Thanks to all.
      Nick
    • By Gary Mier
      1997 Yamaha 350 Warrior, should there be oil in the stator area? Have a no spark situation.
    • By Asen_77
      Hi All,
      My name is Asen and I am from Eastern Europe, Bulgaria. Riding a Yamaha Raptor 700R and this is my first Quad wanted for a vey long time :)

       
    • By jolio
      Just got a '98 Yamaha big bear 4x4 in working condition (so far). Looking forward for some good information on this site about how to keep it alive.
    • By David Goff
      So i have an old yamaha bear tracker that was given to me from an old farmer I know. I decided to refurbished it and fix all the quick fixes on it. I am pretty sure that it is either a 1999 or 2000 based upon the original wiring harness. Little did i know when I bought a new to me wiring harness from ebay that it was from a 2003 or 2004. My question to everyone is do I need to have all the stop switch assemblies hooked up? I think there are three on the 03/04 models and only one on the 1999 to 2000. Any help I can get for this would be great. I haven't run it yet due to the motor and crankcase is in two totes. 


  • Recently Browsing   0 members

    No registered users viewing this page.


×
×
  • Create New...