How do you adjust timing on 140cc dirt bike?

To adjust the timing on a 140cc dirt bike, first, ensure the engine is cool and the bike is on a stable surface. Remove the stator cover to access the timing marks on the flywheel and case. Rotate the engine to align the timing marks, then adjust the stator plate to set the correct ignition timing, usually measured in degrees before top dead center (BTDC). Finally, reassemble the cover and test the engine for proper performance.