YZ426 Throttle Stop?


2 replies to this topic
  • xnofriendsx

Posted September 28, 2005 - 02:55 PM

#1

Sorry for the rookie question, but i was just curious to know what a throttle stop does and if i have one on my 2002 YZ426?
I bought the bike used a few months ago.
I read a lot of posts about the throttle stop on the WR's so they could make them faster, etc.
Just curious as to whether or not my 2002 YZ426 has one and if mine has already been messed with. Or what i can do to change it, etc.
Seems fast enough already.
Anyway of making it less powerful?
Thanks for helping a rookie out.

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  • grayracer513

Posted September 28, 2005 - 03:32 PM

#2

The throttle stop stops the throttle. Because the carb can have the linkage connected with the slide cover removed, it needs something to prevent the throttle from opening so far that the linkage pulls itself apart by moving too far. So yours has one. It stops the throttle from raising the slide past the point where it has completely cleared the throttle bore.

On a WR, the throttle stop prevents the throttle from opening to full throttle so that the bike will pass noise emissions tests (you can't make too much noise if you can't turn the volume up). They benefit from having the stop cut down to YZ length because it lets them boldly go where the YZ's have already been. It won't help your bike, though.

If your bike has an original '02 YZ426 cam in it, you can reset the cam timing to that of a WR426 and make it somewhat milder, if you really want to. ADVANCE the exhaust cam only to a position one tooth forward of the stock timing position. One good thing about this mod is its reversibility. It will knock you down about 3-5 horsepower.

Here's an article on the subjet:
http://motoman393.th...ech/yztime.html
NOTICE THAT the article is written for WR riders wanting to go to YZ timing. To do the opposite, change the last step from "rotate...clockwise" to "rotate...counterclockwise".

  • xnofriendsx

Posted September 29, 2005 - 08:05 AM

#3

Thanks for the reply.
Unfortunately? I have the hot cam in my 426 that was put in from the guy i bought it from. Unfortunately only because i cant knock down the power.
Fortunately cause now i can start the thing way easier.
Pretty sure this adds some horsepower as well, but at least its way easier to start.
Thanks for the info though.

Brian





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