00 426 c/b gear and key fitment ??

3 replies to this topic
  • steepisgood

Posted February 23, 2009 - 05:16 PM


In the process of rebuilding the motor the counterbalance gear is not splined like it should be. I have the key but fits loosely to the crank.

does it have an insert sleeve with splines like a transmission. I don't see anthing like that in the bike bandit schematic.

Am i missing a part or what??


  • grayracer513

Posted February 23, 2009 - 08:36 PM


The '00 and earlier cranks drove the counter balancer with a square key. If you have such a crank, your CB gear should also be set up as a square key drive.

If you have a splined CB gear, it may mean that the previous owner upgraded to an '01/'02 crank, and that you just replaced that with an original design '00. You'll need to swap cranks or replace the gear.

Regarding the key, buy some square key stock at a hardware outlet and make a custom fit key to eliminate the slack, if you build it with the key.

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  • steepisgood

Posted February 24, 2009 - 04:31 AM



thanks for the response. the key looks perfectly square but the drive gear has no splines and and the drive gear fits loosely with the key at the crank. also, it is out of round on the crank because the key appears to make it out of round when fitted.


  • grayracer513

Posted February 24, 2009 - 08:00 AM


If the gear was previously allowed to loosen and rattle on the crank, it may have become worn at its ID, and also may have worn the crankshaft OD where the gear sits. You might want to see how a new gear fits, or if you have the ability to check it, measure the shaft extension for signs of wear.

A number of people have reported finding a poor fit at the key, but the gear should be a smooth slip fit at the loosest.

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