Sierra 18-4274 Prop Spacer for Yamaha Outboard Motors, Replaces 688-45997-01

The Sierra 18-4274 Prop Spacer is a machined replacement spacer designed for Yamaha outboard motors, installed on the propeller shaft between the propeller hub and the thrust hub or prop nut hardware. Its role is to maintain correct axial spacing and alignment on the shaft so the propeller seats properly and hardware such as the prop nut and cotter pin can be torqued and secured as intended. Each package includes one prop spacer.

This spacer corresponds to Yamaha O.E. Part number 688-45997-01 and is built to meet or exceed the fit and performance of the original equipment part it replaces. The compact, precision-machined design measures 0.39 x 0.39 x 0.39 inches and weighs 0.39 pounds, matching the footprint of the original Yamaha component so it drops into place during routine propeller service or hub replacement.

Sierra is a long-established manufacturer of outboard and sterndrive replacement parts, and this spacer is sold as an individual service part for technicians and boat owners performing propeller maintenance on compatible Yamaha outboard motors.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-4274
• Description: Prop Spacer
• Weight: 0.39 pounds
• Product Dimensions: 0.39 x 0.39 x 0.39 inches
• Exterior Finish: Machined
• Quantity Included: 1 spacer per package
• UPC: 030999976536

Fitment

• Yamaha outboard motors

Replaces (OEM)

• 688-45997-01

Frequently Asked Questions

What does the Sierra 18-4274 prop spacer fit? The Sierra 18-4274 prop spacer is designed for Yamaha outboard motors, fitting on the propeller shaft as part of the propeller hub hardware stack.

What OEM part number does the 18-4274 replace? It replaces Yamaha O.E. Part number 688-45997-01, and is built to meet or exceed the original part's fit and function.

How many spacers come in one package? Each package of the Sierra 18-4274 includes one prop spacer.

What are the dimensions of this prop spacer? The Sierra 18-4274 measures 0.39 x 0.39 x 0.39 inches, a compact size that matches the original Yamaha component it replaces.

How much does the Sierra 18-4274 prop spacer weigh? This spacer weighs 0.39 pounds.

Is the Sierra 18-4274 a genuine Yamaha part or an aftermarket part? The 18-4274 is a Sierra-manufactured aftermarket replacement, made to meet or exceed the performance of the original Yamaha 688-45997-01 spacer it replaces.

What finish does the 18-4274 spacer have? It has a machined exterior finish.

Where does the prop spacer install on the outboard? The 18-4274 installs on the propeller shaft of a Yamaha outboard, positioned as part of the hub hardware alongside the propeller nut and related fasteners.

Does the Sierra 18-4274 include the prop nut or cotter pin? No, the 18-4274 package contains only the prop spacer itself; the prop nut and cotter pin are separate Sierra parts.

What is the UPC for the Sierra 18-4274 prop spacer? The UPC for this Sierra prop spacer is 030999976536.