Bad or malfunction causes motorcycle idling instability or non-idling.

There are many possible reasons for motorcycle idling instability or idling failure, mainly involving air filters, carburetors, intake pipes and other hoses, valves, cylinder compression, gasoline, spark plugs, high-voltage electricity and ignition system parts and circuits. If it is an EFI motorcycle, it is also necessary to check whether the ECU igniter, various sensors related to the ignition system and their circuits are faulty. Some of these situations involve many possibilities, and they all need to be checked separately to find out the specific cause of the failure and then repair it as appropriate.

Check whether the filter element and carburetor of the air cleaner are blocked, whether the carburetor is improperly debugged, and whether there is a problem with the supply of gasoline and engine oil.

Check whether the filter element and carburetor of the air filter are blocked, clean the air filter element and carburetor, and check whether the mixing ratio, oil level and oil needle of the carburetor are normal, whether the shock absorber is faulty or improperly used, and whether the carburetor itself is of poor quality or seriously aging. Whether the oil quality of gasoline is bad, whether there are problems with gasoline pump, fuel tank switch, gasoline filter and oil pipe, etc. , resulting in poor oil supply. If it is an EFI motorcycle, check and clean the throttle nozzle.

Check whether the valve and intake pipe are leaking, whether the cylinder pressure is low, and whether there is a problem with the spark plug and high voltage electricity.

Check whether the valve clearance is too small, or whether the valve is not tightly closed due to carbon deposition, wear and ablation, whether the cylinder pressure is low due to the wear of the cylinder block, piston and piston ring, and whether there is slight air leakage in the hoses such as cylinder gasket and intake pipe. Check whether the valve timing is wrong, whether the spark plug is broken, whether the high voltage is broken or weak, etc. If it is an EFI motorcycle, it is also necessary to check whether the sensors related to the ignition system and their circuits are faulty.