Re: Spark plug on 426

9 replies to this topic
  • team yamaha

Posted June 05, 2008 - 03:11 PM


hi recently got a 426 and its keeps fouling my spark plug is thery anyone out there that can help me solve my problum:confused:

  • Markopolo400

Posted June 05, 2008 - 05:53 PM


Don't twist the throttle while the engine isn't running.

  • grayracer513

Posted June 05, 2008 - 08:34 PM


What spark plug are you using?

  • fritzelman

Posted June 06, 2008 - 01:50 PM


Dont know if it will help you, but my 426 had this problem. After a good $20 in spark plugs I had to do something. Turns out, my gasket on my petcock valve on the bottom of the fuel tank was leaking. The carb would fill full of gas and drain into the intake slightly while it would sit overnight. Then when I try to fire it up, the bike would sputter and be flooded.

On another note, make sure you know the starting procedure on your bike. Search the forum here and you can find it.

  • urgreathero

Posted June 06, 2008 - 03:45 PM


u could be runnen ur bike to rich that could be doin it too adjust fuel screww

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Posted June 07, 2008 - 07:23 PM


My 426 use to foul plugs every other ride and I couldn't figure out why. Then I got one of those extended fuel screws and only fouled one plug in 10+ rides. It was my fault anyways because I didn't let the engine warm up before riding :thumbsup:

  • GONE1445

Posted June 08, 2008 - 07:43 AM


also if you start your bike up from time to time like when you store it and dont let it warm up all the way they will foul usually

  • ricky_arthur

Posted June 11, 2008 - 06:57 AM


Are you jetted correctly? Mine did that before I made jetting changes for altitude.

  • Mike Schubert

Posted June 12, 2008 - 11:17 AM


I am running a CR8E and have trouble with fouling sometimes. Has anyone run a CR7E? I am thinkng the extra heat might help.

  • swede426

Posted June 12, 2008 - 02:59 PM


I am running a CR8E and have trouble with fouling sometimes. Has anyone run a CR7E? I am thinkng the extra heat might help.

Should'nt foul plugs if everything is right but I have good experience with CR8EIX

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