00 426 rebuild engine in frame or remove?

2 replies to this topic
  • idl

Posted September 17, 2006 - 05:39 PM


bought a used 426 and finished putting in new clutch, checked valves and a little loose. Would like to check piston and ring. Is it best to remove from frame, or can a check and possible rebuild be done in frame?

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  • 642MX

Posted September 17, 2006 - 05:56 PM


Keep your valves on the loose side of the spec. These DOHC motors tighten the valves up when they wear.

Yes, you can do a top-end in the frame. I've reringed mine many times without pulling the motor.

While you in there, don't forget to replace the timing chain......they are kind of the weak link in the YZF's. They strectch out and eat the crank gear, (the crank gear is made on to the crank half). I replace my timing chain once a year.

Good luck! :thumbsup:

  • idl

Posted September 17, 2006 - 06:34 PM


thanks- timing chain will replace also. Found manual on search, will check carb jets while i'm at it, seemed a bit lean with popping.

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