4 replies to this topic
  • luvmythumper

Posted February 01, 2001 - 01:57 PM


Any recommended jetting for a '01 with an e-series white brothers pipe with 12-14 plates? I ride in Southern calif.


  • Boit

Posted February 01, 2001 - 03:07 PM


If you can describe any abnormal symptoms, you'll get much more indepth advice. What jetting is installed now?

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  • luvmythumper

Posted February 02, 2001 - 08:27 AM


I have not installed it yet. I have stock jetting. I am going to install this weekend. I wanted to know if anyone had already installed this set-up and could help get me started. I am very much an amatuer when it comes to jetting. If it was generally known to go richer/leaner when chaning from a stock set-up to the e-series that would be helpful. Any help is appreciated. Since I have never done this I am afraid I am going to end the weekend with a bike that won't run properly.

  • Hick

Posted February 02, 2001 - 01:43 PM


Since the stock YZ pipe is very unrestrictive the change to the WB probably will not require any drastic changes to mixture other than a slight twist of the idle mix screw. The PC T4 on my 426 seemed to lean things up down low just a tad, but nothing very noticeable.

My advice would be to go ahead and install it, but you may need to purchase a new Yamaha gasket that seals the header to tail pipe section. Once it is on note how the bike runs at various throttle openings and come back to Thumpertalk and post your findings, along with your elevation, climate, type of riding and any other relevant information.

If you have never jetted the bike, pipe or not, you may be missing out on some cheap and easy performance gains. The ’01 is probably jetted pretty good in stock form compared to the ’00, but some guys think a richer main and pilot work better.

FYI I ride in NM dez at about 4,000 ft., ’00 YZF
Main: 162
Pilot: 45
Needle: EKP #4
Idle: 1.75 turns out.

Your ’01 stock is:
Main: 162
Pilot: 42
Needle: EJP #4
Idle: 1.75 turns out.

Since you are likely at a lower elevation I’m guessing a richer pilot and main would work well, but there are some differences between ’00 and ’01 that make the comparison less than perfect.

Hope this helps.

  • motoman393

Posted February 02, 2001 - 04:18 PM


Hey Hick...You said that he may have to buy a new muffler gasket! Well...I needed a muffler gasket also but I was going to have to wait 3 wks for a stupid little gasket (3 wks w/o riding that would about kill me LOL), this is what I did to "JIMMY RIG" it:

I used some header wrap and wrapped it around the header (3 times around was Perfect) and then I taped it on there with a very small piece of duct tape (just so it doesnt move upon installation) I also used vasoline so it would go on easier! Then I just clamped it up and works great! I will get a gasket eventually but I just thought this might help incase someone has to ride the next day and needs a "quick fix"!


I get my kicks on a 2001' YZ426!
Friendswood, TX

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