Thanks all for the helpful comments. I feel well taken care of by this forum! A few responses:
- I don't really care whether the sprocket is a warranty repair or not. When the time comes I'll let Kevin decide. I love the bike regardless, and when I bought it I knew I wasn't buying a precision-engineered Japanese machine, but a piece of history with a modernized powerplant. (FYI, my engine is running absolutely flawlessly at 4,000 miles -- it's the physical infrastructure of the bike, like the drivetrain, where the warts are showing.)
- I understand why pulling away from a stop in 2nd gear for a long time would strain the sprocket teeth (both directly, and indirectly via clutch wear). This is my first motorcycle and I'm still learning good riding and care habits. If CMW decides this is my fault, I'll take my lumps and pay for a new sprocket. Kevin deals very fairly with us.
- I made it home safely last night, although it took hours. I cruised along for about 70 miles at 30-35mph (mostly on the shoulder of I-295 -- when it started to get dark, I moved over onto US 130 for safety reasons), riding as steadily as possible (because pulling on the throttle slipped the chain). FYI, on that tank, riding almost steadily at 35mph for 70 miles, I got the best MPG of my entire 4,000 miles with the bike -- almost 80 (!).
- Then I realized that the chain wasn't going to snap -- that the forces keeping the chain in its plane were strong enough even with broken teeth -- and decided to just tolerate the clattering and ride somewhat more normally. I did the last 50 miles at 45-55mph, more or less with the flow of traffic. There was a sweet spot at around 35mph where I could cruise along (on flat terrain) without slipping the chain as long as I didn't torque the throttle too much. And I discovered that once the bike got above 50mph in moving traffic, it would also cruise without slipping the chain. By the time I got to the outskirts of NYC, I had almost forgotten I had a problem -- I rode the Pulaski Skyway and through the Holland Tunnel almost like normal.
- This does NOT mean that I will ride the bike anymore before it gets serviced. It's parked in the garage. The only riding I'll do will be to whatever dealer I can get to take it in next week.
Thanks again to all of you. The fact that I have this forum to rely on helps me feel safer on the road.