Update (long story short). The Good: Engine is back in business. The timing we did last time was off, the tensioner messed up. Replaced necessary parts and put it all back together and it's good to go. The Auto-decompression works as I imagined it would. Mucho pleased. The Bad: Still no spark. Checked coil, stator, all wiring and everything is good. Manual says to replace little black box (CDI?) up by the radiator on the right side. UGH. Looks like I'll be borrowing an 08 YZ to race this weekend unless by some miracle one of the dealers has that part in stock and it actually is the problem.