What is the average power output of a BSA engine?

You're asking for the average power output of a BSA engine, but that's a very broad question. BSA produced a wide variety of engines over many years, each with varying power outputs.

To give you a more accurate answer, I need more information about the specific BSA engine you're interested in.

For example, tell me:

* What model of BSA motorcycle or other equipment is the engine from? (e.g., BSA Bantam, BSA Gold Star, BSA A10, etc.)

* What year was the engine manufactured? (BSA engines evolved over time, and power outputs changed accordingly.)

* Is it a single-cylinder or multi-cylinder engine?

Once you provide these details, I can look up the specific engine's specifications and give you a more precise answer about its average power output.