You will notice that it hums like a sewing machine (kinda), well
at least it's no longer trying to shake it's self off of the motor
mount. The reason for this smoothness is due to the fact that the engine
is not laboring to spin your propeller at idle RPM. Even with the
propeller installed, the engine eventually will smooth out at around
The clutch assembly consist of two basic components.
The Mechanism which is bolted to the end of the crankshaft and the Drum
which is bolted to the gear box. The mechanism of the clutch contains a
4 pad/shoe assembly which is held retracted with two circular springs.
These springs are tensioned to allow the pads to engage the drum at
approx. 2350 RPM. Clutch engagement is very smooth and positive.
The need for a clutch in the Rotax gear box was
originally developed for the airboat industry where zero thrust at
engine idle was necessary, convenient and extremely helpful during
docking procedures. It didn't take long for the ultralight owner to
appreciate the smoothness offered by this system.
Material of construction is hardened steel. All steel
components are precision machined and deep cadmium plated for superior
The primary purpose of the clutch is to disengage the
prop from the engine allowing it to start and operate at idle without
vibration. When the engine is idling (below 2350 RPM) the prop is not
Installation of the clutch replaces the gear box
flywheel and the hardy disk.
Added weight is approx. 3 Lbs.
clutch is only available in the "C" gearbox.