Sierra Prop Nut Kit 18-3715 - Replaces Johnson/Evinrude 175266

The Sierra 18-3715 Prop Nut Kit is a complete hardware set for securing the propeller on Johnson and Evinrude outboard motors. The kit is built around a brass prop nut and keeper, paired with a cotter pin and a prop spacer, giving you every fastener needed to reinstall or replace worn propeller hardware in one package. The prop nut and keeper are machined brass with an internal #4 UNC thread, finished for corrosion resistance in a marine environment, while the cotter pin locks the nut in place so it cannot back off during operation. Sierra part number 18-3715 directly replaces OEM number 175266, so it drops into the same application without modification.

This kit is sized as a small hardware set, making it an easy on-hand spare for seasonal prop changes, storage prep, or replacing hardware lost or damaged during a prop strike. Because it includes the nut, keeper, cotter pin, and spacer together, there is no need to source each piece individually or guess at compatible sizing.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-3715
• Product Type: Prop Nut Kit
• Material: Brass
• Thread Size: 1/4 inch
• Inside Thread Size: #4
• Thread Type: Unified National Coarse (UNC)
• Thread Style: Internal, #4, Right Hand
• Finish: Machined
• Color: White
• Item Dimensions: 0.39 x 0.39 x 0.39 inches
• Weight: 0.44 pounds
• Kit Contents: Prop Nut/Keeper (18-3708-1), Cotter Pin (18-3741), Prop Spacer (18-4231)

Fitment

• Johnson/Evinrude outboard motor

Replaces (OEM)

• 175266

Frequently Asked Questions

What does the Sierra 18-3715 prop nut kit include? The kit contains a brass prop nut with keeper (18-3708-1), a cotter pin (18-3741), and a prop spacer (18-4231), giving you the complete set of hardware needed to mount a propeller.

What OEM part number does 18-3715 replace? Sierra 18-3715 replaces OEM number 175266 on Johnson/Evinrude outboard motors.

What engines is this prop nut kit designed for? This kit is designed for Johnson and Evinrude outboard motors.

What material is the prop nut made from? The prop nut and keeper in kit 18-3715 are machined brass.

What thread size does the 18-3715 prop nut use? The prop nut has a 1/4 inch thread with an internal #4 Unified National Coarse (UNC) thread, right hand style.

Is a cotter pin included with this kit? Yes, the Sierra 18-3715 kit includes cotter pin 18-3741 to lock the prop nut in place.

How much does the 18-3715 prop nut kit weigh? The complete kit weighs 0.44 pounds.

What color is the prop nut kit? The Sierra 18-3715 prop nut kit has a white finish on the packaging/nut components as listed by the manufacturer.

Does this kit include a prop spacer? Yes, prop spacer 18-4231 is included along with the prop nut, keeper, and cotter pin in kit 18-3715.

Is Sierra 18-3715 a genuine aftermarket replacement or OEM part? Sierra 18-3715 is an aftermarket replacement kit engineered to replace OEM number 175266 on Johnson/Evinrude outboards.

What are the dimensions of the individual components in the kit? Individual hardware pieces in the 18-3715 kit measure approximately 0.39 x 0.39 x 0.39 inches.