Replacement wood ruff key for the UMS 9-99cc, the nine-cylinder 99cc four-stroke radial from UMS.
Function: it is the Woodruff key, which keys the propeller drive to the crankshaft so torque is transmitted positively.
The reason this ends up on an order: a sheared key is the usual result of a prop strike, and a worn key allows the drive to fret on the shaft. Supplied as a pack of 4, which is how these small parts are normally bought — you rarely need just one.
Fitting note: Check the keyway in both the shaft and the drive for fretting before fitting a new key.
Reviews
There are no reviews yet.