Why Does a Motorcycle Stall When Accelerating While Cold?

[LeSilas]

Motorcycles stalling when accelerating while cold are mostly caused by a clogged carburetor. Remove the carburetor and clean it thoroughly, ensuring all spray holes inside the carburetor are unclogged. Additionally, check if the spark plug and high-voltage electricity are functioning properly, whether the vacuum membrane in the carburetor has issues, and if the engine's air-fuel mixture ratio is correct. Below are two common scenarios of motorcycle stalling: 1. The first scenario: The engine stalls due to an overly rich air-fuel mixture. Simply put, an overly rich mixture means the engine is injecting too much fuel, which could be caused by a faulty oxygen sensor or inaccurate air intake measurement. In this case, the motorcycle usually stalls due to ignition system failure or fuel system issues. 2. The second scenario: The engine stalls due to an overly lean air-fuel mixture. An overly lean mixture means the engine is injecting too little fuel. Unlike the first scenario, this happens when the needle seat and foam tube fall into the fuel pool, preventing the needle from rising with the plunger. As a result, insufficient gasoline is supplied, making the mixture too lean to ignite. This often leads to stalling during operation.