Changing cam timing to a YZF spec

8 replies to this topic
  • shahar

Posted March 25, 2003 - 01:33 AM


I own a WR426F yamaha model 2002.
I have modified it and made a lot of performance and weight changes.
I have read at "dirt-bike" magazine that I can change my cam timing to YZ426F spec. what chnges do I have to make? what way do I have to move the cams? how many teeth?
Thanks Shahar

  • Indy_WR450

Posted March 25, 2003 - 04:45 AM


Search this forum for the information it is there and also look at Motoman 393 technical bulletins on the main web page of

  • xrracer36

Posted March 25, 2003 - 07:32 AM


"do a search,... do a search,... do a search..."
is that all anyone knows how to do around here anymore?
is it so difficult to just tell the guy what he needs? :)

anyways, :D
just turn the exhaust cam one tooth clockwise to get yz timing. big performance gain.
racer36 :D

  • shahar

Posted March 25, 2003 - 08:02 AM


Thanks a lot man !!!


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  • MOmilkman

Posted March 25, 2003 - 08:31 AM


I have found out this week that its not just as easy as turning the exhaust cam 1 tooth clockwise. Anyways it isnt for me.

I learned you have to re-jet to YZ specs. And remove the octupus if you havent already.
Hope you know more about lean YZ jetting than I do.

I wish it was as easy as turning the cam. :)

  • Indy_WR450

Posted March 25, 2003 - 10:03 AM


To Xrracer36:
I am not trying to be an ASS! But your answer is idiotic at best. When you stand on the left side of the bike or right side of the bike clockwise has 2 different meanings. The reason I recommended the search is that there is a lot of detailed information on this forum that some people prefer to have. You could have provided a link to the answer if you did not like my approach. I am sorry you are having a bad day. I was just trying to help and I did not feel your comment was warranted

  • tctrailrider

Posted March 25, 2003 - 11:15 AM


Try this site, its for the WR250 but the info is all the same.

  • xrracer36

Posted March 26, 2003 - 05:18 AM


easy indy.
i gaev the guy the info i know. if he needs more, he can do a search. but i was at least pointing him in the right direction as to what would be involved and what he was getting into as far as i know.
i been on this board for a couple years now, and sincei been on, these were the problems that i have spent time reading solutions to. it just seems that these days nobody wants to help each other like they used to. whether it be from too many new members who don't know how to do anything cuz they haven't been here long enough, and want to sound all hi tech by suggesting a search or what, i don't know, but sometimes a search produces 14,000 replies, and the majority of us just don't have the idle time to browse thru them all to find the one with the proper tech articles needed.
IN REPLY TO "IDIOTIC AT BEST": as for i tooth clockwise, if you are timing your bike, i should hope you are looking at the timing marks on the sprokets (left side of bike), which would make clockwise equal spinning your cam to the right.
i don't wanna start anything here. i was just stating an observation. TT members just don't seem as willing to take the time to answer tech questions like they used to. it almost seems like the search of the archives has made members of this site lazy.
i know sometimes i feel better witha fresh response about soething that deals with the engine in case there has been some discovery of an error with an old post or technique that wasn't updated in te old search material.

take it as constructive criticism, or hate mail, or what ever you want.
just my $.02

racer36 :)

  • tk421

Posted April 01, 2003 - 12:40 PM


Watch out for the bearing retainers (they can easily fall into the engine) :), and be careful not to over tighten the camshaft caps.

I used these illustrations when I changed mine to YZ timing.

Posted Image Posted Image


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