Counterbalance key

7 replies to this topic
  • schony

Posted March 15, 2010 - 08:00 AM


Dose anyone know what the part number is for this? I am rebuilding my 400 and here this is a problem? do i have to split the case to do this? I saw 1 key one each end on the crank in an exploded view but none on the balance shaft?

  • motodiver13

Posted March 15, 2010 - 08:22 AM


What exactly is the problem? I just did one and don't recall any key or keyway on the counterbalancer.

  • grayracer513

Posted March 15, 2010 - 09:58 AM


The balancer itself doesn't have one. The balancer drive gear on the crank of 2000 and earlier models uses a square key that gets beat up and then damages the crank. The one you see on the right end of the crank axle is the one you want.

It is not necessary to remove the engine or split the case to install it.

  • motodiver13

Posted March 15, 2010 - 10:22 AM


Thanks Grey, I did not remove the gear from the balancer shaft.

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  • schony

Posted March 15, 2010 - 09:13 PM


the cam journals got really scored up and this dude wanted to get rid of the bike so I bought it for 200 bucks. Bought a new head and a set of hot cams plan to get the cylinder done to a 420cc and wanted to do any other upgrades that it might need. so this key is it item 90280-03017-00? Any other suggestions are welcomed thanks for the help guys!

  • schony

Posted March 15, 2010 - 09:15 PM


not a "new" head but a good used i should say

  • grayracer513

Posted March 16, 2010 - 07:28 AM


so this key is it item 90280-03017-00?

I don't see that number anywhere. It varies with year model, what's yours?

Item # 9 on the crankshaft page.

  • schony

Posted March 16, 2010 - 10:36 AM


Thanks Gray, that's exactly what I wanted to know :banana: .


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