Requirements for a 200cc two-wheeled motorcycle engine can include the following:

1. Horsepower and Torque: A 200cc engine generally needs to provide the right amount of horsepower and torque in order to drive the motorcycle and maintain good performance. Normally, the maximum power of a 200cc engine should be between 10-15 horsepower and the maximum torque should be between 12-14 Nm.

2. Fuel efficiency: Fuel economy needs to be considered when designing the engine, because the fuel consumption is directly related to the user's operating costs. Therefore, the 200cc engine should be economical and durable to meet the user's fuel consumption requirements.

3. Cooling system: The engine needs to be kept cool to avoid overheating and failure. Therefore, a 200cc engine usually requires an effective cooling system, such as a water cooling system or an air cooling system.

4. Reliability and durability of the engine: The engine needs to have sufficient durability and reliability to ensure that users will not encounter failures and problems when using the motorcycle. This requires engine designers to pay attention to material selection and manufacturing process during the design process.

5. Emission Standards: Engines should comply with local emission standards and regulations to avoid negative impacts on the environment. Therefore, 200cc engines usually need to be equipped with exhaust gas treatment equipment, such as catalytic converters or exhaust gas recirculation systems, to meet local emission standards.