Front sprocket question

11 replies to this topic
  • sharpmarble

Posted May 02, 2005 - 10:28 AM


I'm putting new sprockets on my bros YZ426, what size is the nut on the front sprocket?

Help me out, I put forth this question in my forum but apparently no one has heard of this!!!! :naughty:

  • MotoGoalie

Posted May 02, 2005 - 11:31 AM


It's really big. Its about a 26 or 27mm on a 03 YZ450f.

  • jamieyz426f01

Posted May 02, 2005 - 11:34 AM


its a 28mm on the 426 mine was a right pain to get off, it would have been easier with an impact driver!.

  • grayracer513

Posted May 02, 2005 - 12:38 PM


Twenty-seven millimeter.

  • 99YZ400F

Posted May 02, 2005 - 02:42 PM


27mm, is that the same as on a 99 400F? (not to hijack your thread or anything)

  • grayracer513

Posted May 02, 2005 - 03:04 PM


Might be. It's the same on both my YZF's and all the other later YZ's I've popped 'em off of.

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  • flintlock28

Posted May 02, 2005 - 03:08 PM


Is the screw a normal right hand thread, or is it reverse????


  • 426panzer

Posted May 02, 2005 - 03:15 PM


Not a reverse thread...

  • flintlock28

Posted May 02, 2005 - 03:16 PM


Thanks for the info, panzer.............

  • copsey

Posted May 02, 2005 - 03:16 PM


Right hand threads. It's a 27 back to 97 and possibly earlier if I remember correctly. I know the 2000+ are 27's.

  • jamieyz426f01

Posted May 03, 2005 - 07:46 AM


yea sry bout that it is a 27mm :naughty:

  • sirthumpalot

Posted May 03, 2005 - 03:53 PM


Normal thread. Air wrench takes it right off (leave the tranny in neutral), or leave the chain on and have a buddy stand on the rear brake while you loosen it with a wrench.

Almost forgot; don't forget to pick up a spare flat lock washer for the front sprocket. It's a flat washer and after you tighten the nut you have to bend it over the nut to keep it from loosening. They usually have several sides that can be bent so you can reuse it once, but if it has already been reused then you'll need a new one.

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