What Causes a Scooter to Stall When Throttle is Released?

[Lori]

A scooter stalling when the throttle is released may be due to the engine idle speed being too low, or it could be caused by air leaks in the engine leading to insufficient fuel supply. Below are the relevant explanations: Idle Speed Too Low: If the issue persists after the engine has warmed up, you should check whether the idle speed is set too low, or if the fuel mixture ratio is incorrect. A clogged carburetor or air leaks in the intake pipe can also cause the engine idle speed to be too low. Engine Air Leaks: Air leaks generally occur due to poor sealing between the carburetor and the engine. The sealing condition of the spark plug, cylinder head, and crankcase directly affects the engine's performance. Over time, the carburetor can become clogged, which may also cause the engine to stall. If the carburetor is severely clogged, it is recommended to replace it directly, as adjustments cannot fix inherent carburetor issues. Another possible cause is insufficient fuel supply. The entire fuel line, from the fuel tank to the carburetor's main jet, needs to be thoroughly cleaned and inspected.