Glossary of Outboard Motor Terms

Cubic Centimeters (cc)

A unit of measurement for the displacement of the engine, which helps identify its relative size.

Gear Ratio

The ratio of the RPM of the engine to the RPM of the propeller.

HP

Same as “horsepower.” This is the unit of measurement for the power your outboard motor produces.

Hull

This is the body of a ship or boat.

OHV

Same as “overhead valve”, an improved way to control exhaust and intake valves on internal combustion engines.

RPM

Same as “revolutions per minute.” The amount of revolutions (turns) an engine makes in one minute.

Transom

This is the back of the boat where the outboard motor is positioned. This height is usually measured from the top of the rail to the bottom of the boat.