1999 YZ400 change cam timing to WR

2 replies to this topic
  • kanyonkritter

Posted January 16, 2009 - 12:15 PM


It seems I am looking to go in the other direction, I have seen lots of threads on changing a WR cam timing to match YZ cam timing but am looking to go the other way. The low end on the bike is unacceptable for the type of riing that will be done with this bike. So my question is I remember reading somwhere that you could change the cam timing on the exhuast cam by 1 tooth or was it 1 degree?????IDK if that is the case which way should I rotate the cam to produce the desired results?

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  • maxtherat

Posted January 16, 2009 - 10:29 PM


You would advance the timing of the exhaust cam one tooth, counter clockwise facing the sprocket side. At TDC your cam lobes would be at just above 9:00 for intake and just above 3:00 for exhaust. Another suggestion would be to add fly wheel weight or the cheapest alternative would be to decrease the counter sprocket size by one tooth. Obviously this will slow you down on the top end.

  • tntmo

Posted January 20, 2009 - 11:38 AM


Another option would be to find a WR400/426 rider who wants to convert to YZ specs and trade parts (cam, flywheel)


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