yz426 WB e series jetting specs???

10 replies to this topic
  • mr426

Posted August 04, 2007 - 03:18 PM


hi, i bought my bike with an e series(not e2) but i dont think the guy jetted it for the new muffler. it has a low/mid range bog. i am running 6 discs with a spark arrestor. does anyone have the jetting specs that should have came with this exhaust when it was purchased??? my bike is mostly stock and my pipe is also stock.

  • mr426

Posted August 04, 2007 - 05:44 PM


anybody? any help is appreciated.

  • mr426

Posted August 06, 2007 - 05:53 PM


WOW! no one has the jetting specs from WB??? i cant find them anywhere...

  • 642MX

Posted August 06, 2007 - 06:17 PM


What are your current jetting specs?

  • Dustin_Mabro

Posted August 07, 2007 - 04:49 AM


I have the same thing, bought it that way and the guy had no clue. A local part slinger told me his setup was the same and he had luck with stock jetting and then he 'jets with the plates'. I've had luck with 6 plates and stock jetting (a little rich) but this is Michigan, a long ways from Cali. Good luck

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  • Daz_426_02

Posted August 07, 2007 - 06:06 AM


Hello Mr426, I had the same problem with mine. Even Bought a JD Jetting kit (which was big $$$) to try and fix it. In the end i found that the packing was too tight in the can and after repacking it with new packing it was perfect. My WB can was also brand new never fitted but was packed too tight. Give it it try, worked for me.

  • jayh300

Posted August 07, 2007 - 07:10 AM


hey mr426.... i will check my paper work on the "e" and see if it has any...
will post back after lunch.

  • jayh300

Posted August 07, 2007 - 10:32 AM


no jetting specs in the sheet i have for my e

  • mr426

Posted August 07, 2007 - 08:48 PM


the packing can make a difference??? i bought a stock muffler on ebay for 15 dollars, im gonna see if it runs right all stock and then tune for the wb pipe accordingly. i really want to buy a fmf q silencer so my wb is for sale if anyone wants it, i have 17 discs and a s/a for it. 100 bucks takes it...

  • Daz_426_02

Posted August 07, 2007 - 10:23 PM


Believe me the packing can make a difference.
If it is too tightly packed as mine was (also a new silencer) the air will not go into the fibers but rather straight out.

I doubt you will find jetting specs because they are designed to be used with the stock set up. I was in communucation with WB R&D department about my problem for a few days and they were also confused as to why i had a huge flat spot/bog.

With mine when i first put the can on there was a massive flat spot at the bottom end. Mid range was good as was the top end of the rev range. So i took it off and forgot about it. When the time came to replacing my stock packing i had some FMF packing left over and thought i would try it in the WB silencer. Which i did and it worked 100% no bog or flat spot what so ever. On any of the replacment packing packets you buy it says "Do not over pack the exhaust because it will effect performance and sound control"

  • mr426

Posted August 08, 2007 - 01:08 PM


i will try to repack it then. how tight should it be?

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