Timing on these guys is pretty simple. On the back of the engine, there is a stamped cover. Under that is a pick-up coil that triggers the ignition. This bike uses a magneto type arrangement and does not need a battery to run.
On that pickup, is a mark that should be aligned with the mark on the crankcase. THAT is the only timing you will need to set. You might try to advance it but for the most part, in my experience, it has hurt the performance.