I took my bike to get fixed this morning. Four mechanics had ten different ideas of what to do to fix it. At the first shop the two mechanics said the problem was the chain and sprockets and general wear and tear; they wanted to do a full service tuneup for hundreds of dollars, and only then figure out what the problem was. But they would have taken several days to order the parts, so I went to another shop down the road, where the mechanic said it was probably a slipped clutch, so he could rebuild the clutch but it would take a week...so he referred me to a friend of his at a third shop, where I ended up leaving it. It was a cool shop - a very small operation, not a huge fancy dealership like the first one - just one guy in a real mechanic's shop, old parts and grease and a loft for the office. After checking a few things out and listening to the problems he said the sprockets were fine, the chain was terrible, it had nothing to do with the clutch, but it was probably related to the plugs and the air filter. At the previous tuneup in Arizona they replaced three of the plugs but couldn't get the fourth out because it was stuck (all these guys frowned when I told them that; I guess if it's really stuck they need to tear the threads and drill new ones which is really complicated).
The bottom line is, I don't know much about mechanics (I really should but I'm afraid I'll screw it up if I try learning by myself), so I should have gotten a full service (not just a tuneup) several thousand miles ago. The bike has been burning oil lately, too, which I should have realized was a symptom of bigger problems. This mechanic (Sean at All Makes Motorcycles) replaced all four plugs, and said that the shop in Scottsdale had put the wrong kind of plugs in. He replaced the chain and ordered a new air filter, which should arrive tomorrow. Apparently when the bike fell (as it has several times), oil saturated the air filter which ruined it. Of course there's no guarantee that the problems (knocking, loss of power, burning too much gas and oil, etc) will all go away with these repairs, but my fingers are crossed.
I should really take a mechanics course. Maybe I should buy an old crappy 50cc bike just to mess around with it as a learning tool. I'd need more tools and lots of space to work, not easy in Boston. Considering that Zen and the Art of Motorcycle Maintenance is one of my favorite books, I'm pretty terrible at maintaining my own bike. (I check the fluid levels and lube the chain regularly, but there's a lot more to good maintenance than that.) Sean said the worst case scenario is that the top end of the engine will have to be rebuilt. That would cost $1000 at least. The bike's only worth $1500 in good condition now, so if that's the case it won't even be worth fixing it. I really hope it's not, though, because this bike has sentimental value now that I can't put a monetary value on.
As for my schedule, I'll get the bike back tomorrow afternoon, then stay up most of the night watching election results. Thursday morning looks like the most reasonable departure time. I had wanted to get back to Boston by next weekend but that's not possible. Hopefully the weather will still be good (above freezing) when I get back and Tristyn will forgive me for being away so long. I still have sites to see going up the east coast but I'll try to put in many miles each day between them.