I've just been to look at my neighbours Honda Big Red quad, as it had developed starting problems. The electric start stopped working a while ago, so he'd just been using the kick start, which also packed in a couple weeks ago. Somebody else had already removed the crankcase/clutch/kick start cover, but that is all they done, as they weren't sure what they were looking at. On first looks, the engine could only be turned the one way by grabbing the centrifugal clutch bell (the clutch roller for the kick start goes between the clutch bell and crankshaft), and after a bit head scratching we realised the roller clutch would only turn the engine the wrong way. After looking at a part diagram, we took the centrifugal clutch off to get access to the roller clutch to see if anything obvious was wrong with it, but it looked fine. Flipping it over, allowed the engine to be turned the correct way (or at least the clutch work the right way, the engine still wouldn't turn the right way!). The mystery of the engine only turning the wrong way, was found to be a bearing in the starter motor drive had collapsed, and a ball was jamming the gears acting as one way clutch, only allowing the engine to turn the wrong way. With all the balls recovered, the engine now spins in both directions. However, would overloading a roller clutch cause it to reverse direction? I don't really want to rebuild it, and find the roller clutch suddenly flips direction again, as I'm pretty sure that could result in some quite catastrophic results if it happens at high revs. Nobody else had had the clutch assembly apart, as the nut for holding everything onto the crankshaft was still pinned in place when I removed it.