1977 XL75 startup issues?

[Magnar]

My girlfriend just bought a '77 XL75 this weekend. We got it home, got it started once. It did have a bit trouble idling, then the engine cut, so we filled her up with some 93 (I figured it may have had gas sitting in it for a bit, can 93 to rich for this bike? Never heard of gasoline being too high octane, but I thought maybe this'd be part of the problem.) I just can't seem to get her to start. The startup and idling problems remind me of all the choke/carb problems I had with my '89 YJ Wrangler, but I can't find a decent schematic to locate the choke, and I don't want to destroy the carb due to ignorance. If anyone has any advice it would be much appreciated. The neutral light/turn signal/horn all work fine with the key turned. However, the headlight would only turn on when the engine was running. I've kinda discredited any electrical problems for now, since it was starting up before, which means the coil and magneto are probably clean, and all the wiring seems to be acceptable. Once again, any help would be greatly appreciated.

Thanks!

[Qqqqqqqqqqqq]

Probably a blocked carb