My chain has recently come loose on my '02 Virago 250. I started noticing it after I stalled out accidentally while trying to start in second gear. It makes a weird squeaky noise while I´m coasting and downshifting. The bike still runs fine, but I worry that I'm doing more damage by continuing to ride. Do you think I just need to tighten the chain or could it be another problem? If it is just the chain, how do I tighten it?