Procedure: Rotate the crankshaft to Top Dead Center (TDC) on the compression stroke (both rocker arms loose). Use a feeler gauge between the rocker arm screw and valve tip. Loosen locknut to adjust.
If your engine is difficult to start when cold or makes a "ticking" sound, your valves likely need adjustment. 0.05mm Exhaust: 0.07mm lifan 1p54fmi service manual
Believe it or not, third-party publishers sell generic "Chinese OHV Engine Repair Manuals." Look for titles like "Chinese 125cc OHV Engine Repair Guide" — these often use the 1P54FMI as the primary example. Procedure: Rotate the crankshaft to Top Dead Center