How to compare the ignition time of pedal 125?

Ignition is generally electronic ignition, and no adjustment is needed. You should be talking about the adjustment of valve timing. There is a line engraved with a capital F on the rotating shaft of the magneto. Align it with the round hole on the air guide cover. At this time, the piston is just at the top dead center, and the intake valve and exhaust valve are completely closed.

By the way, cleaning the hood means removing the cylinder head cover with four screws. The two small holes on the timing gear are parallel to the rocker arm frame, and the big hole is forward. Is the T-shape on the flywheel aligned with the prominent mark on the engine?

Only when the hood is removed can you see the mark. It's on the right side of the refueling.