wr 426 missfiring and high idle

3 replies to this topic
  • tamme

Posted February 13, 2006 - 11:05 AM


I got a WR 426-01 with stock pipe and I cant get the bik to run proerly, it starts perfect on choke, and sounds ok, but when i get of the choke it starts to "poff" in the silencer an runs pretty porly, it getts a bit better as the engine gets warmer,
as i get of the gas the idle is still hangin at about 3000 rpm and stays there for about 10 sec. bvefore it gos down to "good" idle an about 5 secs later it stals.
I cleand the carp like 1000 times and checked the jetting, it it stock! I did go up on tje slow jet 5steps but no differance.
it dosn´t matter how the mixture is, it dosn´t react on anything.

Need help...


  • BC61

Posted February 13, 2006 - 05:44 PM


Check your hot start button. If it is not closing and sealing properly it can cause these types of problems.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • Gerry B

Posted February 13, 2006 - 07:22 PM


I agree with BC61. Sounds like the hot start is stuck open.

  • killroy

Posted February 13, 2006 - 10:32 PM


Ok, thanx
Is the piston simular to the choke? I mean, the choke has a rubber sealing on the top of the piston, but not my hot start.
Are they supposed to be that way? or are the piston sealing missing?


Related Content


Snake pit oct 30th by The Anvil

Dirt Bike   Dirt Bike Regional Discussion   California
  • Hot  293 replies


Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • Hot  30 replies

Wilson the Blue Privateer by jetfuel

Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  50 replies

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.