426 engine question

6 replies to this topic
  • RPB

Posted May 13, 2009 - 01:50 PM


Iv'e searched many different words and phrases and couldn't find an answer.:doh:

Bike: 00 426 with a blown engine that pretty much destroyed the entire bottom end and maybe the top end also.

Are all 426 bottom ends the same? Can I get one from any year 00-02 that will work?

Couple of teaser pics. Damage is far worse than you can tell by the pics.
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  • RPB

Posted May 13, 2009 - 02:39 PM


I think I found what I was looking for. It looks like the swingarm bolt is different on an 02 than on an 00 or 01. Other than that, they are the same. I think. :doh:

  • grayracer513

Posted May 13, 2009 - 02:42 PM


So, you broke the balancer gear, did you?

The '00 is different in on respect: The '00 used a square key to locate the balancer drive gear, while the '01/'02 uses splines. As a result, the crank itself is a different part, as is the balancer drive gear.

Otherwise, the parts of all 3 are pretty much interchangeable.

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  • RPB

Posted May 13, 2009 - 03:17 PM


That is not all that broke. The broke gear pictured is the one from behind the gear on the crankshaft. There was onther complete gear that was just floating around inside the case. All the gears have damage done to them, the case has a few holes from gears bouncing around, the clutch basket is toast, the top end is beat up but fixable.

I am not really worried about the balancer gear as much as I am the cases. This case is beyond repair (not really beyond repair but would need alittle welding to fill in some of the holes and some TLC) so I want to replace the whole bottom end so I can just bolt it into the frame.

We still haven't really pinpointed the exact cause.

  • finthat

Posted May 13, 2009 - 03:33 PM


My guess is the tranny self destructed. Or something siezed and then everthing else started letting go.

  • grayracer513

Posted May 13, 2009 - 08:16 PM


We still haven't really pinpointed the exact cause.

I will boldly guess that the bolt that feel out of the counterweight fell between the balancer drive gear and the oil pump idler.

  • RPB

Posted May 14, 2009 - 08:55 AM


For the record, it is not my bike. I actually maintain my bike.

I don't think it was the bolt because the bolt has virtually no marks on it and I don't think it was the trans because it shifts fine. Prior to it seizing, it sounded like something was rattling around inside there. The dude that was riding it rode it for a while with the rattling sound and you could tell something was bouncing around on the inside from all of the nicks and dings inside the case.

What we think happened was the circlips on the shaft that hold the oil pump gear? let loose and that caused a chain reaction. The shaft that is supposed to be where I put an arrow was missing (in the other side of the case) and that gear was just floating around inside. No c-clips were found.
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