10 replies to this topic
  • Adam

Posted September 23, 2001 - 05:15 PM



i have a 2001 yz426 and i bought it in june after a month of riding my bike started to make a studering noise when i have the bike full throtle but only in 1, 2 and 3 gear would you have any idea what this is and how i can fix it.


  • sirthumpalot

Posted September 24, 2001 - 12:02 AM


Is it hitting the rev limiter?

  • Adam

Posted September 24, 2001 - 08:58 AM


i don't think i have a rev limiter
but if u can tell me what it looks like and how to take it off i could try that.

thanks "sirthumpalot

  • sirthumpalot

Posted September 24, 2001 - 09:52 PM


It's built into the ignition system, I do not think that we can adjust it. If the engine starts to rev too high then it will start to cut the spark and the engine will sound like it's stuttering or missing. This can happen in any gear but is more likely to happen in lower gears because there's less load on the engine and it can rev easier. Does your bike only stutter when it's revving very high, or at any RPM?

  • Adam

Posted September 25, 2001 - 09:41 PM


Only at high RPM's when i hold it wide open. When i get it full throtle its all right but when i hold it then it starts.

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  • sirthumpalot

Posted September 25, 2001 - 01:10 PM


I haven't heard your bike so I can only speculate from here, but from what you have posted it sounds like you're hitting the rev limiter to me. Try shifting earlier!!

  • Bill

Posted September 25, 2001 - 03:36 PM


Sounds like your hitting the rev limiter. It's a four stroke that makes gobs of low end......shift.

The only time I hit mine, is if the straightaway is not long enough to shift and gain anymore speed ie by the time I shift up, I have to slow for the corner. I try to ride the same gear for as much of the track as possible. You be surprised at how slow you can go and have the bike pull out of a corner with NO clutch.


99 WR400f, YZ timed, MX-Tech suspension, Scotts steering damper, White Bros E-Series (12 discs), tapered header and a/f. Kouba T-handle for the fuel screw. Works Connection billet throttle tube and frame guards. Cycra Pro-Bend, triple clamp mount handguards. Thumper Racing rad guards, Renthal Jimmy Button highs, YZ Tank and IMS seat, YZ number plate, odo removed, de-octopussed (Thanks Clark) EKP #4, 50PJ, 175MJ, 100PAJ and 65 SJ at 500-1000' Thanks James Dean!

  • Taffy

Posted September 25, 2001 - 10:17 PM


try dropping the needle a clip and if that works do it again.

you may want to come down one or two jet sizes if it's what i think it is.

let us know.


  • sirthumpalot

Posted September 26, 2001 - 02:59 AM



I see what you're getting at (maybe he's lean on top) and you have a good point, but I'm not sure the needle clip would help here since he's got it wide open. I think it would be more of a main jet issue in this case. Very good point though. :)

  • yzernie

Posted September 26, 2001 - 06:28 AM



It sounds like you're at the rev limiter to me too. You don't need to rev this bike like that and as Bill said it has tons of low end power.

Sounds like you have switched from a 2 stroke where you need to rev them like that. Riding a 426 is all about using the torque to your advantage. Continued over rev (like riding on the rev limiter) is hard on the valve train.

Shift earlier and learn to love the engine.


  • Adam

Posted September 26, 2001 - 10:19 AM


I found out that it is my main jet and that i need to go up two sizes i was runing lean.
thanks guys for your knowledge and ideas.

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