Jason, did your mechanic take the compression reading? Is there any resistance when you kick it over? You should always do a thorough tune up prior to making any radical decisions. For one thing it gets you to focus on things you may over look jumping to conclusions. If your mechanic is telling you it needs it I'd tend to believe him. You can do a wet and dry test on it to see if it is the valves or the rings but usually I end up doing both because I'm in there any way. You should replace the timing chain as well as it isn't any extra work and is an $11 part. One thing about paying a mechanic to do the work on these bikes is that the amount it cost to do the work will soon out run value of the bike.

Hoo