The maintenance steps of the chain saw:

A: Re-adjust the oil needle, tighten the L needle and loosen it by half a turn, and tighten the H needle and loosen it by a half turn.
B: Exhaust air, causing oil to flow out of the carburetor.
C: Pull the fire five or six times, and then remove the spark plug to see if there is any oil.
D: If there is oil, it proves that there is a problem with the circuit (replace the spark plug, if it still can’t be solved, replace the coil assembly)
E: If there is no oil, the oil path is blocked (check the fuel tank cap, the oil pipe filter, whether there is any blockage in the carburetor, check valve, whether there is a pull cylinder, or the oil seal is leaking)