Crankshaft

This is the Crankshaft, often called the "heart" of the engine.

If the piston is the legs of the engine, the crankshaft is the pedals. It takes the "up and down" (linear) motion of the piston and converts it into "round and round" (rotational) motion to drive your wheels.

Anatomy of this Crankshaft:

• The Connecting Rod (Con-rod): That’s the black metal arm sticking out to the right. The piston attaches to the top of this rod.

• The Crank Webs (Flywheels): The large, heavy circular weights. These use momentum to keep the engine spinning smoothly between power strokes.

• Main Bearings: You can see a ball bearing pressed onto the shaft. These allow the crankshaft to spin at thousands of RPM inside the engine case with minimal friction.

• The Tapered End/Keyway: The long shaft in the foreground has a slot (keyway) where the automatic clutch or a magneto/flywheel would sit.