Baja Warrior - Jackshaft key going out every ride

[Lupo]

Hey everyone,
My buddy Tim purchased a baja warrior and the thing keeps shredding its jackshaft key. (Never have a problem with my 6.5 baja doodle)

I'm not sure if the name is 100% correct but its basically just like a clutch key that allows it to get torque from the drive shaft. Anyone one that is familiar with the larger baja bikes there are two sets of chains. The jackshaft key causes the back wheel's sprocket to disengage and loses all power to the back wheel. I know the ultimate tweak / fix is to convert to a torque convertor but I wanted to see if anyone experienced this before and if there are any other alternatives.

He picked up a couple dozen clutch keys to keep on hand but its rather annoying that it breaks every 20 minutes. Also the main nut that holds the smaller sprocket to the key and sprocket to the larger chain becomes loose every time he goes through a key.

 

[junkcollector]

If there is any rotating slack in the shaft and sprocket and any wear in the key slots when you speed up and slow down the slack rotates power push power push if you grab a hand full of power after letting off the slack could sheer the key off level with the slot a pic of the problem area might help ? just some thoughts good luck

 

[xxllmm4]

I would guess the key is too small and causing some slop. You could weld the gear on. Or try some green locktite. Or heat the key up with a torch and wack it with a hammer to make it a little thicker then file it down to get a perfect fit.

Jordon