The MTD 75115204 Ignition Sensor, also known as a magneto, is a genuine MTD replacement part. This small, black, plastic component is crucial for engine operation, located under the flywheel. It is responsible for generating the signal that triggers the spark plug to create ignition. A faulty ignition sensor can prevent the engine from starting or cause it to run poorly. This part is compatible with various engines found in MTD, Cub Cadet, Troy-Bilt, and Craftsman outdoor power equipment.