actually guys..... that bolt IS MADE to stretch, it is a tension bolt, meant to torque to a certain value, and provide tension to hold the outer half of the clutch to the inner half of the clutch. the reason your bolt broke is because the outer half of the clutch was spinning and slipping under the bolt, which ended up tightening the bolt tighter and tighter untill the bolt had stretched to its max, and snapped the bolt. we used to see this alot on the older CAN-AMs which had the aluminum spyder. the aluminum spyder slipped alot against the steel inner shaft when you put alot of power to it. this made the outer half spin and tighten the bolt untill the bolt stretches to its max and snaps. BRP tried to remedy this on the maverick by implementing a steel outer tapered sleeve into the aluminum spyder. the steel on steel taper fits and sticks much better than the steel on aluminum like the other bikes. even though these two steel tapers SHOULD stick permanantley and keep the clutches from slipping, they do not, and the result is that the clutch still slips like the older setups, and stretches the bolts untill they break.
BRP cuts the middle of the aluminum spyder out and rivets in a steel sleeve that has a steel taper
this steel taper fits against a steel female taper (and slips)
here is what the bolt looks like after it stretches
here is the fix (more like a band-aid) to help keep the bolt from breaking. running a big stud that is not necked down. but the clutch will still slip, and tighten the bolt, regardless of what bolt you run. thats why replacing the stock primary was so popular on the commanders and ATVs. you almost HAD to replace the clutch just to get a good day of riding in. the maverick clutch is doctored up better, and will last longer, but still suffers from the same things the commanders clutch did