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• I've just received this new part. When diagnosing a fault it's easier to understand what's broken when you know what a part is supposed to do in the first place. The term "centrifugal clutch" is misleading to me as I automatically compare it to a car clutch where the engine is connected or disconnected to the gearbox and wheels. That's what a clutch does, disconnects drive. The following is my best guestimate looking at the new part - I believe the mechanism in the splined pulley end acts as a brake when the motor is turned off, to quickly stop the blades from spinning. NEW PART: The central spline and pulley wheel are one combined plastic piece. The pulley has raised edges to confine the belt from falling off, the same as the small motor pulley. Inside the pulley body you can see 2 metal arms which are each hinged at one end (attached to the pulley) and are heavily sprung to push hard inward against the bearing casing (which is part of the entire plastic frame). This makes the pulley hard to turn by hand. I assume when the motor spins up, it initially works hard turning the pulley with the brakes on, once a certain speed is reached the centrifugal force pushed the internal brake arms outwards (against the force of the spring), so they are no longer braking against the bearing housing, allowing full speed and removing the strain from the motor. OLD PART: Has a cast Alu pulley wheel, with a flat edge so nothing to confine the belt from falling off the edges. It has a separate white plastic central spline section that could turn around 90 degrees within the pulley against a spring, I assume internally there was a braking action of a similar type connected to the white plastic spline (which is now stuck on causing the impeller and blade not to turn). When spun up the brake would release, when the motor stopped the spring would push the brake back on and stop the blade turning quickly. Regards, Mark. By Mark H - Scotland - 11 September 2015