ORIGINAL: MONAROMAN
Well unfortunately I wasn't running the stock carrier, i was running the vertigo one
with brand new bearings, shimmed up with minimal play and didn't even get time to heat up in most cases (I am talking literally 3-5 mins runtime in some instances). I tried a different carrier and it still happened, tried stock gearing, different bells, overhauled drivetrain with new bearings and checked for drag or binding - all to no avail. Basically the drivetrain (which includes that pesky little 4mm bolt) was designed to take the stock engine's 2 odd HP and low torque, now we run 4-5 HP engines with truckloads more torque without even blinking an eye. For me, with my setup the 5mm bolt fixed the issue, and it will for all those in a similar situaton to me.
well obviosuly the issue wasn't with the Vertigo carrier [sm=rolleyes.gif] if you tried another brand alloy one and it still happened. You were probably over torquing the bolt like alot of guys end up doing to keep it on since the star lock washers that go underneath are junk. Problem is if you torque it down too much you strain the bolt and when the gears warm up they expand a little which along with vibration can be enough to break it.
You're not understanding how your engines torque load is transmitted through the drive train, you could run an engine twice the power of the one your using and it won't strain that bolt any more then stock because the engines load isn't transmitted laterally on the bolt, its just a retaining screw to keep the pinion on the clutchbell shaft nothing more. The slot on the end of the CB's shaft and the corresponding groove on the pinion gear take the torque load, which at that point in the drive line really isn't all that compaired to the other end.