The scooter won't catch fire. What happened?

There are many possible reasons why the scooter can't catch fire, mainly involving cylinder pressure, concentration and quality of mixed gas, high voltage electric intensity and so on. , each aspect involves multiple parts and multiple possibilities. It is necessary to investigate each possibility involved in these aspects separately, find out the specific cause of the failure, and then repair it as appropriate. The three basic conditions for motorcycle starting are proper concentration of mixed gas, accurate and strong high-voltage electric spark and good compressibility.

If the scooter doesn't catch fire, first check whether the high voltage electricity is normal through the spark plug and high voltage line. If there is no high-voltage electricity, or the high-voltage electricity is obviously too weak to break the fire, it is necessary to check whether there is any problem with the spark plug, high-voltage bag, igniter, stator coil of magneto and electric lock of ignition switch. And whether the wiring between these ignition system components is open or short-circuited, whether the wiring plug is loose, etc. And whether the ignition timing/valve timing is correct. If it is an EFI motorcycle, it is also necessary to check whether there are any problems with ECU and various related sensors and circuits related to the ignition system.

Check whether the filter element of the air cleaner is soaked in oil or blocked, and whether the carburetor is blocked. Clean the carburetor, and check whether the mixing ratio, oil level and oil needle of the carburetor are normal, whether the electronically controlled damper can add rich mixture normally, and whether the quality of the carburetor itself is too poor or there are other faults. Check whether there is enough gasoline in the fuel tank, whether the quality of gasoline is poor, whether the switch of negative pressure fuel tank is normal, whether the switch of negative pressure fuel tank is damaged, and whether gasoline seeps from the oil suction pipe to cause flooding. If it is an EFI vehicle, check whether the throttle nozzle is blocked. Check whether the suction pipe of the negative pressure tank switch leaks oil, which leads to no oil supply, and whether the hose between carburetor and engine leaks oil.

Check whether the cylinder block, piston and piston ring are worn, resulting in insufficient cylinder pressure, too small valve clearance, or air leakage due to carbon deposition, wear and ablation, which is a common problem of scooter. Check whether the engine oil and oil circulation lubrication are normal, whether the cylinder is pulled or stuck, whether the exhaust pipe is blocked, poor cylinder compression and poor air intake and exhaust are also common reasons why the scooter cannot start.