What are the reasons why a motorcycle is difficult to start when cold?
2 Answers
Motorcycle cold start difficulties can be caused by unsuitable engine oil, clogged air filter, excessively small valve clearance, etc. Specific reasons are as follows: Unsuitable engine oil: In general cold start issues, engine oil is the first consideration. Inferior quality oil not only fails to provide heat resistance, cooling, and lubrication for engine components, but also presents a semi-solidified state in cold conditions, directly causing the engine to fail to reach the required cold start RPM. Clogged air filter: An air filter that is not maintained in time and remains clogged or semi-clogged will not only cause cold start difficulties but also significantly affect the overall lifespan of the engine. Excessively small valve clearance: If the valve clearance is too small, the engine cylinder pressure will be insufficient, making it difficult to start the motorcycle when cold.
When the weather gets cold, my motorcycle has trouble starting, and I've noticed many fellow riders face the same issue. The fuel system is crucial here; the carburetor can easily accumulate gum and clog the fuel lines if left unused for a long time, especially when using low-quality gasoline. On the electrical side, insufficient battery voltage affects the starter motor's speed, and the battery's activity drops significantly in winter. If the spark plug gap is incorrect or there's too much carbon buildup, the ignition energy is directly reduced in low temperatures. There's also the issue of oil viscosity—using 40-weight oil in summer makes it too thick in winter, increasing internal engine friction and causing starting difficulties. It's recommended to kick the ignition lever a few times before a cold start to warm it up, and regularly check the battery and switch to winter-grade oil for noticeable improvement.
