In this video, I explain how an impulse coupling works on aircraft magnetos. Impulse couplings play a crucial role in helping aircraft engines start by delivering a hotter spark at lower...

Apr 2, 2025 · Impulse coupling: A spring-loaded assembly between the magneto and the engine that helps an engine start at low speeds by delaying spark timing and accelerating the speed of the rotor …

Therefore, some magnetos have an impulse coupling, a spring-like mechanical linkage between the engine and magneto drive shaft which "winds up" and "lets go" at the proper moment for spinning the …

The purpose of the impulse coupling is: . To snap the magneto through its firing position so it produces a spark even though the engine is being slowly cranked.

The angle E of an impulse coupling is determined by the location of the keyway in the hub; the lag angle can be increased or decreased within limits by moving the keyway when making the hub.

Dec 29, 2025 · Brian Carpenter from Rainbow Aviation Services discusses the magneto impulse coupling and shows its component parts and how they operate to generate spark and aide in starting …

Nov 13, 2018 · The impulse coupling mounts between the magneto and the engine, allowing it to control when the magneto rotates. The coupling has a couple of spring loaded flyweights that catch on a …

The impulse coupling will function adequately during engine start even though the coupling is worn. Starting performance is not an indicator of coupling wear condition.

Brian Carpenter from Rainbow Aviation Services discusses the magneto impulse coupling and shows its component parts and how they operate to generate spark and aide in starting your engine.

The impulse couplings are a spring-loaded component that aids in engine starting by accelerating the rotating magnet and retarding the timing. Having an impulse coupling that is not functioning properly …