Last month, after replacing my alternator (strator) cover with an OEM unit, I got this terrible chattering noise from behind the cover when I went to start it. This happened after I had started and ridden the bike a few times since the cover was changed. I immediately stopped trying to start the bike and pulled the cover. It wasn't confirmed, but I'll bet my life it was the gear you see in the attached picture walking on the dowel. I took the dowel out and looked at the gear. Luckily, no shavings or any damage to the gear. I reinstalled it and was fine for another few weeks. Then, on my way to get tires put on last week, it made the noise again. Problem was, I had to be at my appointment and had no time (or tools) to fix it. Against better judgement, I started the bike with the chattering noise and road it about a mile before downshifting back to first, which stopped the chattering. I since took the bike out two more times and have parked it. I really want to get rid of this problem. One mechanic told me that the dowel comes loose on Yamahas (common problem). There are no c clips, e clips, or otherwise. The dowel is held in by the cover and the gear slips over the dowel. I was thining about holding the dowel in with some oil-proof RTV. Any other suggestions or comments? I'm looking at 1 and 2 in the picture.