Boat › Outboard › Propeller

Without a working propeller an outboard motor can't move a boat at all. Important characteristics of a propeller are its pitch and diameter, the number of blades it has, the number of splines in the hub and the material it is made out of.

The video below shows how to measure the pitch and diameter of a propeller.

How to measure a propeller's pitch and diameter

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Measure the pitch and diameter of an unknown propeller, such as one from a scrap yard. I mark two-thirds of the radius on the blades, plot the rise on cardboard and read the hub code.

Spun propeller bushing

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This topic covers the situation where the propeller is not spinning at the same speed as propeller shaft, therefore reducing forward thrust.