OMC Evinrude Johnson Propeller Nut

The Part number 314503 for OMC Evinrude and Johnson outboards is a propeller nut. It's a castle nut or a pin-type nut used to secure the propeller to the crankshaft. Specifically, it's a set of two, often sold together as a pair. These nuts are typically found on motors with 13 splines, such as those with 14, 25, and 28 horsepower. 

Key features and notes:

Function: Secures the propeller to the crankshaft.

Type: Castle nut or pin-type nut

Compatibility: Typically used on Evinrude and Johnson outboards, especially those with 13 splines.

Important: When changing a propeller, it's important to inspect the nut, the splines on the crankshaft, and the bushing for wear and damage. Make sure there's adequate lubrication on the splines before reinstalling the propeller.