Awww, it was something stupid. I tightened the spark plug an eighth of a turn and it started.
Now that I got it running, it has no torque, so it won't pull me up my driveway, and bogs when I open it up.
I'm not sure, but I may have put the exhaust back on incorrectly.
I don't suppose anybody knows how to get the cylinder block off the transmission housing on one of these things? I kinda snapped off one of the engine studs, and I can't get near it with the screw extractor to get it out and replace it.