yzf426 with yzf 450 cams will it work?

6 replies to this topic
  • austin82

Posted April 21, 2009 - 09:32 AM


Hi I'm looking for somebody to give me a answer to my cam question. I own a 2002 426 yzf but would like to convert it to auto de-comp. After reading and searching almost every thread about 426 de comp questions I still haven't found any answer.
Will cams from a 2006 450f yamaha work on my 2002 426?

Any help with my question will be appreciated.:banghead:

  • grayracer513

Posted April 21, 2009 - 01:59 PM


The exhaust cam will, although the cam from an '03-'05 will produce slightly better low end power. Not a real big difference, but there is one.

You don't want to use the 450 intake, however. For one thing, there isn't a lot of difference in them, and for the other, there's no way to time them without one of the original 426 cams, since the 450 timing marks don't line up with the 426 head correctly. The timing procedure, which you must have read by now, is to time the stock intake, then spot the exhaust in with the two top marks on the cams 14 pins apart. The timing of the ex cam will look wrong, but it won't be. Without the stock intake as a reference, you would need to use a degree wheel.

  • GM3coupe

Posted April 22, 2009 - 12:54 AM


alright Austin lad :banghead:
imagine finding you here!

have a look at these threads:-

The Decompression Cam Mod (DCM) (for 400/426's Only) (This info does not apply to YZ/WR250F models)
Link to Instructions:

Clarification of "DCM" Timing Instructions

The whole, original 450 DCM Thread:

How Auto Decompression Works in a YZF:

How to Start a YZ426 (Video with Doug Dubach- Special Thanks to Yamaha Motors, and all the Good People at Dubach Racing Development)
(Requires QuickTime, or a player that will handle QT videos)
Part 1: (Cold Start) http://www.yamaha-mo....roke_vid_a.mpg

Part 2: (Hot Start) http://www.yamaha-mo....roke_vid_b.mpg


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  • grayracer513

Posted April 22, 2009 - 06:10 AM


You can't copy the displayed text of a URL when it includes "..." and have it work.

The threads above are all listed in Common Threads, at the top of the index for this forum.

  • austin82

Posted April 22, 2009 - 09:26 AM


Thanks for your help. The reason I wanted to check about the 06" cams is that there the only cams I've found for sale at the moment. I read up about the 03" cam conversion but didn't mention anything about fitting 06" cams. I belive that 07" and onwards will not work. Just checking before I part with any cash.

  • grayracer513

Posted April 22, 2009 - 11:23 AM


I belive that 07" and onwards will not work. Just checking before I part with any cash.

They will also fit, and would be timed by the same procedure. However, starting with the '06, each year up to '08 had cam timing progressively more biased toward high end and less toward low end. The cams would fit, but the question is how the cam timing would work as far as performance.

  • robjones69

Posted May 11, 2009 - 06:38 PM


I installed on 08 YZ450F exhaust cam into my son's 01 YZ426F last night, and as long as you follow the instructions and diagrams from this site, it all works really well.

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