Running a motorcycle with the choke on for an extended period of time can potentially cause damage to the engine. The choke is designed to restrict the airflow into the engine, enriching the air-fuel mixture for easier starting and warm-up in cold conditions. Once the engine warms up, the choke should be gradually disengaged to allow for proper air and fuel flow.
If the choke is left on while the engine is warm or operating at normal temperature, it can lead to an overly rich fuel mixture. This can result in incomplete combustion, fouled spark plugs, carbon buildup in the combustion chamber, and potentially damage to the catalytic converter (if the motorcycle is equipped with one).
While it's not uncommon to use the choke for a brief period during cold starts or warm-up, it's important to gradually disengage it as the engine reaches operating temperature. Running the motorcycle with the choke fully engaged for an extended period, especially under normal operating conditions, can lead to performance issues and potential damage over time.