WR cam mod vs YFZ cam mod??


5 replies to this topic
  • Blue4Ever

Posted June 17, 2006 - 12:20 PM

#1

Just curious? I have understand you can not change the exhaust cam timing on the WR's w/auto decomp due to the pin length and the timing of when it opens the valve. What I am curious about is why you can make this mod to a YFZ in 04 and 05, which I have done many w/o issue and they still start very easy. It seems that a YFZ would suffer the same effect as the WR by advancing the cam. Has anyone determined the difference. :excuseme:

  • simon@vic

Posted June 17, 2006 - 04:03 PM

#2

if you where to advance the cam on a yz it wouldn't work..................

on the wr426 you would advance the cam so it would sit like the yz cam.
with a wr450 you have to buy a yz450 cam.

  • MountainMax

Posted June 17, 2006 - 04:46 PM

#3

so the Yz cam is a different profile and at different cam timing as well (more advanced I guess right) If you advance the Yz cam more it will be advanced too much right?

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  • nitronaf

Posted June 17, 2006 - 07:37 PM

#4

Just curious? I have understand you can not change the exhaust cam timing on the WR's w/auto decomp due to the pin length and the timing of when it opens the valve. What I am curious about is why you can make this mod to a YFZ in 04 and 05, which I have done many w/o issue and they still start very easy. It seems that a YFZ would suffer the same effect as the WR by advancing the cam. Has anyone determined the difference. :excuseme:

hmm well i just had a quick look at the quads cam part numbers for 06 vs the wr
vs the yZf they are slightly different
2006 YFZ450 5TG-12180-20-00
2006 WRF450 5TJ-12180-20-00
2005 YZF450 5TA-12180-00-00

  • Blue4Ever

Posted June 18, 2006 - 02:19 PM

#5

so the Yz cam is a different profile and at different cam timing as well (more advanced I guess right) If you advance the Yz cam more it will be advanced too much right?


Actually I was refering to the quad (YFZ) not the YZF bike. I have retarded the exhaust cams on many 04 and 05 YFZ's(quads) that have auto decomp w/o any problems. Why is it that the WR's w/auto decomp have a problem w/the decomp pin opening the exhaust valve to early and the YFZ w/auto decomp does not have this issue? The different part #'s most likly refer to different lift and durations. I would think the auto decomp pins would contact about the same time in rotation weather they are YFZ's or WR's?! :excuseme:

  • Matty05

Posted June 19, 2006 - 03:26 AM

#6

the pin is shorter in the YZF and longer in WR cams, the YFZ pin might be short too?




 
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