Hard to start when cold

In the morning or in cold weather, you have to crank it for a long time, hit the starter repeatedly, or use the choke several times before the engine catches; but once warm, everything's fine and it starts right up. This cold/hot contrast is very telling: it almost always points to an enrichment or ignition problem when cold, exactly when starting conditions are toughest. When cold, fuel vaporizes poorly, parts are at their widest clearances, and the battery delivers less current: the engine needs a richer mixture and a strong spark. The main causes are therefore: a cold-enrichment device (manual choke or automatic enrichener) that's stopped working, a slightly weak battery (cold reduces its capacity, and the starter struggles), a worn spark plug (that manages fine when hot but struggles cold), or a partially clogged idle circuit that starves the engine of fuel right at the critical moment of starting. Useful distinction: if the bike starts perfectly once warm, the problem is cold-related (enrichment, idle circuit); if it's hard when hot too, look toward the spark plug or battery. And depending on whether the starter cranks the engine vigorously or weakly: a weak starter points to the battery, a vigorous starter with an engine that won't catch points to enrichment or the spark plug. Urgency: no danger, but worsening cold starting often signals a battery or spark plug nearing the end of its life, best addressed before it fails completely.