Why can't Ruifeng m5 start?

Hello, my friend, there are many engine jitter factors. Suggested check: 1. Whether the spark plug is damaged; 2. Whether the engine is carbon-deposited, clean the throttle and nozzle, etc. 3. For the problem of oil, it is suggested to use this box of oil to go to a regular gas station to refuel and try the effect again; 4. Whether the idle motor is abnormal; 5. Whether the air intake system is abnormal; 6. Whether the battery is short of electricity and the circuit is damaged; Please check the above items for your reference.