What is the purpose of an impulse starter in an engine?

The purpose of an impulse starter in an engine is to utilize a coil spring mechanism to temporarily increase the speed of rotation of the magneto at startup. This increased rotational speed is essential because it helps to create a stronger magnetic field, which generates a higher voltage necessary for producing a spark at the spark plugs. This spark is crucial for igniting the fuel-air mixture in the engine cylinders, enabling the engine to start more efficiently.

By employing this design, the impulse starter allows for reliable ignition, especially in situations where the engine may initially struggle to turn over quickly enough for proper magneto function. This is particularly advantageous in aviation engines, where reliable and consistent starts are vital for safe operation.