converting 02 yz426 to a 440

5 replies to this topic
  • robg

Posted March 23, 2007 - 09:59 AM


I'm planning on converting my 02 YZ426 into a 440. The reason is just to use it for endurance ice raceing. The question is has anyone done the conversion ? How was the reliability? Bottom and mid? Just wondering. I will probably be cheaper in the end to use this bike instead of wrecking a new one. To answer the question of why not just buy a new bike.


  • Birdy426

Posted March 23, 2007 - 02:09 PM


I have the luke's raqcing 440 kit on my 426 (actually, I thought it was 444...) The reliability has been great...about 2000 trouble free miles.

  • 642MX

Posted March 23, 2007 - 05:18 PM


They are 444 kits, here is the link. http://www.lukesraci...uksr/yz426f.htm

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  • robg

Posted March 25, 2007 - 08:01 PM


thanks guys

  • robg

Posted March 25, 2007 - 08:02 PM


where do you notice the difference

  • Birdy426

Posted March 26, 2007 - 11:39 AM


where do you notice the difference

Everywhere! I went up a tooth on the c'shaft sprocket because there was so much more torque that first gear was useless. The motor is a bit slower to rev (though not much), but has so much more poop everywhere. Gear too high going up a hill? No worries, just blip the throttle...two gears too high? No problem, just blip the throttle. Need a top end uincrease? No's there.

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