Once you back off the tension on the belt (move rear wheel forward) the front pulley will come off fairly easy. Don't forget to loosen the nut first.
It should be fairly obvious looking at the splines in the pulley and the shaft as well as the fit on the shaft. There should be no laterial movement of the pulley on the shaft.
I have read about metal fatigue in that pulley on other forums but Scootworks admits to nothing. They did however give me a $250.00 trade in on the old system to the new system so there might be something to the fatigue problem.
I'm still in debate with them over that as well as the finish on the rear pulley/sprocket.
I'm on holidays right now or I would post some pictures of the rear sprocket where the paint all pealed off around the six nuts fastening it to the hub. I also have pictures of the output shaft but not the front pulley. Scootworks has the front pulley because you have to ship back the belt and pulleys to get the trade-in for the Brute force system. All my pictures are on my other computer, it will be a week before I can get back to it to post them.
Replacing the shaft is no easy task. The whole engine has to be dismantled. Shaft, bearings, seals, gaskets etc run around $800.00 plus labor.
Let me know what you find.
Dave

 

I should mention I have another thread here under engine vibration 800 Classic. Just a little problem since I started down this road. I can't do anything tell I get back from holidays.
Dave

 

Have you had a chance to look at your drive pulley/sprocket yet? And the output shaft splines?

 

Any updates on your problem?