Why does a motorcycle fail to start when it's cold?
2 Answers
Solutions for a motorcycle engine failing to start when too cold are: 1. Check the carburetor, fuel mixture ratio, fuel level, and choke; 2. Inspect whether the valve clearance is too small or if there is air leakage; 3. Check if the high-voltage spark for ignition is strong enough; 4. Open the choke to force start. The reasons why a motorcycle engine fails to start when too cold are: 1. Low cylinder pressure, leading to poor atomization of the mixture provided by the carburetor or fuel pump at low temperatures, making it difficult to ignite; 2. High engine operating resistance at low temperatures. Methods to prevent a motorcycle engine from failing to start when too cold are: 1. Replace the engine oil with a lower viscosity oil suitable for winter use; 2. Clean carbon deposits.
My over ten years of riding experience tells me that the most common issue for not starting in cold weather is the battery. Cold temperatures significantly reduce battery power, especially for old batteries that have been used for two years—the starter motor turns particularly slow. Carbon buildup on spark plugs is another major problem; winter ignition requires stronger sparks, and too much carbon buildup can prevent starting. For older carburetor bikes, pay attention to the choke—cold starts require pulling the choke, and if the choke cable gets stuck, it’s troublesome. Engine oil is also crucial; in winter, you need thinner oil with a 10W rating, or the engine simply won’t turn over. My bike wouldn’t start before, but it worked after replacing the spark plugs and cleaning the carburetor. Remember to charge the battery once a month as part of regular maintenance.
