converting 2001 wr426 timing to yz spec


11 replies to this topic
  • wr426Ripper

Posted November 16, 2009 - 07:31 AM

#1

(2001 WR 426 FN) I want to CONVERT TIMING TO YZ SPEC. AND CUTTING THE GREY WIRE. GETTING RID OF THE WR AND YZ DUAL MAPPING. SUPPOSEDLY, CUTTING THE GREY WIRE BYPASSES WR MAPPING? PLEASE ANY INFO CAN HELP HERE. RETARDING EXHAUST TIMING ( TURN EXHAUST CAM ONE TOOTH TO THE LEFT/RIGHT? SHOULD I CUT GREY WIRE IN CONJUNCTION WITH EXHAUST CAM TIMING MOD? PLEASE HELP!!!!!!

  • grayracer513

Posted November 16, 2009 - 08:12 AM

#2

(2001 WR 426 FN) I want to CONVERT TIMING TO YZ SPEC. AND CUTTING THE GREY WIRE. GETTING RID OF THE WR AND YZ DUAL MAPPING. SUPPOSEDLY, CUTTING THE GREY WIRE BYPASSES WR MAPPING? PLEASE ANY INFO CAN HELP HERE. RETARDING EXHAUST TIMING ( TURN EXHAUST CAM ONE TOOTH TO THE LEFT/RIGHT? SHOULD I CUT GREY WIRE IN CONJUNCTION WITH EXHAUST CAM TIMING MOD? PLEASE HELP!!!!!!


Looking at the sprockets from the left side, the engine and cams rotate forward, which is counterclockwise, or to the left, from that viewpoint. To retard a cam, you want it to arrive at a given point in its rotation later in relation to the crank, so you rotate it one tooth "backward", which is to say clockwise, or to the right, relative to the crank and the intake cam.

http://motoman393.th...ech/yztime.html

As to the gray wire mod, opening the gray lead does change the timing map to a more aggressive, performance type timing, but it's not YZ timing per se, since the WR CDI is not used on YZ's.

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  • l_campionero

Posted November 16, 2009 - 08:19 AM

#3

I don't know how similar my 99 WR400 is to your 01 426, but other than a YZ pipe and related jetting changes, it was stock, and fast as a rocket!
Good luck!

  • wr426Ripper

Posted November 16, 2009 - 08:34 AM

#4

Ok thanks for the info. But like on a car. you can move cams without loosening the cap bolts. Do I have to loosen them to move the exhaust cam gear just one tooth? when I cut the grey wire do i just cap both ends. I dont connect them to anything right?

  • l_campionero

Posted November 16, 2009 - 08:38 AM

#5

You have to loosen the cap bolts, otherwise you can't get the cam sprocket free of the chain. Make a mark with a felt tip marker to know where you are in relation to the original position.
On my 2007 wr250f, I just pushed the gray wire's connector out of the multi-plug, and taped it out of the way, so I could reconnect it later, if so desired.

  • wr426Ripper

Posted November 16, 2009 - 08:43 AM

#6

Im confused ! Wont releasing the tensioner give enough slack to turn the cam gear? I want to spin the gear and cam together right? I dont want to seperate the gear from the cam. Just want slack to spin the gear one tooth.

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  • l_campionero

Posted November 16, 2009 - 08:46 AM

#7

You don't have to separate the gear from the cam, in fact, it's pressed on, but you will have to take the cam loose from the head. The tensioner won't give enough slack....at least in my experience.
If it is possible to do it otherwise, I'd like to know also.
Regardless, it's not that big a deal.

  • wr426Ripper

Posted November 16, 2009 - 08:51 AM

#8

Ok cool. Thanks for the help. I machanic on cars and am now seiing they are similar but not the same. I will go foreword with this mod and see what happens. This bike is already fast and strong and I only weigh 175 pounds. But, you know we always want more.

  • wr426Ripper

Posted November 16, 2009 - 08:53 AM

#9

Between the exhaust timing mod and cutting the grey wire, Is the difference huge in the power and torque respects.

  • l_campionero

Posted November 16, 2009 - 08:55 AM

#10

Seriously, I'd disconnect the gray wire first, then consider the cam timing change for later. Get a used YZ pipe and change the jetting to YZ specs, and it will probably be fast enough.

  • wr426Ripper

Posted November 16, 2009 - 08:56 AM

#11

cool thanks.

  • Jonny426

Posted November 16, 2009 - 01:15 PM

#12

Consider a YZ exhaust cam from Hot Cams...the auto decompressor feature is well worth the price. there is a BIG difference in top end power with YZ timing




 
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