BK mod, Boysen AP, valve check....

3 replies to this topic
  • DTYZ426

Posted February 20, 2006 - 10:34 PM


2001 YZ426F

Had the carb off for cleaning today, so I went ahead and did the BK mod, so simple, installed the Boysen AP cover, checked valve clearances, perfect :thumbsup:

BK mod: 4mm x 25mm allen bolt, spring, washer, drill bit, tap about 20 minutes to complete. AP squirt went from at least 3 seconds to .4 seconds.

while I have the bike torn down I want to do the 450 exhaust cam upgrade.

so, does anybody have the 03 450 cam for sale?

  • jbrooks26

Posted February 20, 2006 - 11:13 PM


There were several on E-bay the other day, if no one here has one you might check there. I also think you can get it from TT OEM for somewhere around $100. Hope this helps.


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  • DTYZ426

Posted February 21, 2006 - 05:33 AM


thanks, I've been watching ebay, but nothing yet.

  • olliemills

Posted February 21, 2006 - 09:42 AM


what is the BK mod?

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