wr timing a yz

8 replies to this topic
  • tool

Posted June 06, 2004 - 07:23 PM


i was searching for some info and found nothing. im making my yz into an enduro bike and want to change cam timing to wr specs. i have 00 stock yz cams.
i really dont know which cam to change or which way to change it. do i change both cams? any help would be appreciated

  • stevie

Posted June 07, 2004 - 04:02 AM


I installed a wr cam in my 03 YZ450. It gives smoother power making the bike easier to ride. You need to only change the exhaust cam, I think its the one with 3 lobes (correct me if i am wrong it was ages ago). Its easy to and you just line up the dots as normal like it says in the manual.
If I were you I would get an 03/04 WR cam then you would also have the advantage of auto-decomp. Just a thought

  • tool

Posted June 07, 2004 - 10:56 AM


no, no... im talking about changing my stock exhaust cam 1 tooth, one way or the other, to achieve WR timing. i guess you would retard the exh camshaft? but i remeber hearing the wr is more mellow because of a retarded intake timing?? not exhaust... :thumbsup:

  • Butta

Posted June 08, 2004 - 09:11 AM


Nope, the intakes are the same, it's the exhaust cam that is slightly different. One tooth, and I'm not sure which way it goes (I'd explain it wrong for sure). I used my WR exhaust cam in my YZ motor because the one that was in there had a slipped gear so the timing marks weren't lining up right. Anyway, if you look at the actual position of the lobes, you can figure it out. I'm sure there are people on here that have a TON more info on it.

Definitely the exhaust cams, though.

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  • tctrailrider

Posted June 08, 2004 - 09:19 AM


http://motoman393.th...pertalk.com/<br />

Check the above link, tech articles and YZ timing.

  • tool

Posted June 08, 2004 - 01:23 PM


so, i get from that motoman site that for WR's you advance the exhaust timing 1 tooth. and for YZ's you retard the exh timing by 1 tooth. meaning that WR's middle dot on the cam would now be at 1:00, and the YZ's middle dot at 11:00.
my cam dot looks more like 11:30, but i can see that its only rotated 1 tooth. is that right? i guess ill just see if it starts.

  • tctrailrider

Posted June 08, 2004 - 02:11 PM


WR timing will have 13 chain pins between the 12 oclock punch marks, YZ timing has 12. Rotate the exhaust cam one tooth counter clockwise and your YZ will be WR timed.

  • tool

Posted June 08, 2004 - 04:20 PM


well, it must be right because it fired right up and had a stronger idle. i guess it revs slower, but the response off idle is faster... so it revs very similar. then i rode it.
incredible... so much more torque, :thumbsup: very noticable. no mid hit and no upper end hook, just a smooth rev all the way from idle to the limiter. but i cant say i lost power anywhere, just lost the zip.
i do ride some mx, but i dont see this mod hurting that. (i play race only) i now have a do-it-all bike. :awww:

  • Butta

Posted June 08, 2004 - 04:37 PM


It's so funny....several years ago it was always the WR guys trying to make their bikes like the YZ's (power wise, anyway)...now, here we are with 450's making INCREDIBLE power, and it may actually be too much... interesting, isn't it?

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