Sierra 18-4228 Prop Spacer, Replaces OMC 315810, for Johnson/Evinrude Outboard Motors

The Sierra 18-4228 Prop Spacer is a metal spacer designed to fit on the propeller shaft of Johnson/Evinrude outboard motors, positioning the propeller correctly between the shaft components. It is manufactured from metal for durability and is built to withstand the salt water and fresh water conditions typical of outboard motor use. This spacer is a direct replacement for OMC part number 315810, making it a straightforward swap when rebuilding or servicing a propeller assembly. As a small but essential hardware component, the prop spacer helps maintain proper spacing and alignment along the propeller shaft, supporting correct thrust washer and prop nut engagement during reassembly. It ships as a single unit and is commonly replaced alongside other prop hardware such as the prop nut and cotter pin during routine propeller maintenance. Because propeller hardware is exposed to constant water contact and mechanical load from the spinning propeller, using a correctly sized, corrosion-resistant spacer like the 18-4228 helps ensure the propeller stays properly seated and the shaft assembly performs reliably. This part is intended for Johnson/Evinrude outboard motors and is sold as a genuine Sierra replacement part identified by OEM equivalent number OMC 315810.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-4228
• Item Type: Prop Spacer
• Material: Metal
• Engine Type: Gasoline
• Operation Mode: Manual
• Recommended Use: For Salt Water
• Mounting Type: Engine Mount
• Fuel Type: Gasoline
• Unit Count: 1 count
• Weight: 0.02 pounds
• OEM Equivalent Part Number: OMC 315810

Fitment

• Johnson/Evinrude Outboard Motors

Replaces (OEM)

• OMC 315810

Frequently Asked Questions

What is the Sierra 18-4228 prop spacer used for? The Sierra 18-4228 is a metal spacer that fits on the propeller shaft of Johnson/Evinrude outboard motors to position the propeller correctly during reassembly.

Is the 18-4228 a genuine Sierra part? Yes, 18-4228 is Sierra's own manufacturer part number for this prop spacer, not a generic aftermarket copy.

What OEM number does the Sierra 18-4228 replace? It replaces OMC 315810, so it is a direct equivalent for that OEM prop spacer number.

What is the 18-4228 spacer made of? It is made of metal, providing the durability needed to hold up under the constant water exposure and mechanical load of the propeller assembly.

Will the 18-4228 fit any outboard motor? The 18-4228 prop spacer is designed for Johnson/Evinrude outboard motors specifically.

How much does the Sierra 18-4228 prop spacer weigh? The Sierra 18-4228 weighs 0.02 pounds.

Do I need to replace other prop hardware along with the spacer? Many installers replace the prop nut and cotter pin at the same time as the 18-4228 spacer since all three are part of the same propeller hardware assembly, though each is a separate Sierra part.

How many spacers come in a package of the 18-4228? The 18-4228 is sold as a single prop spacer, with a unit count of one.

Is the 18-4228 spacer compatible with saltwater use? Yes, the Sierra 18-4228 is recommended for use in salt water conditions.

How is the 18-4228 prop spacer installed? It is installed on the propeller shaft as part of the standard propeller reassembly sequence, positioned per the outboard's propeller hardware stack.