Sierra 18-3715 Prop Nut Kit

SKU: 4001947 - UPC: 030999316363 - MPN: 18-3715
$24.99 $31.89 ( / )

Available Stock : 9

Essential Hardware for Secure Propeller Performance Keeping your outboard motor's propeller firmly in place is crucial for smooth operation on the water. This prop nut kit provides the reliable components needed to ensure your prop stays locked during high-speed runs or rough conditions. Designed for durability, it replaces worn or...
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Sierra 18-3715 Prop Nut Kit Product Description

Essential Hardware for Secure Propeller Performance

Keeping your outboard motor's propeller firmly in place is crucial for smooth operation on the water. This prop nut kit provides the reliable components needed to ensure your prop stays locked during high-speed runs or rough conditions. Designed for durability, it replaces worn or lost parts that can lead to vibrations, slippage, or even propeller detachment—issues no boater wants to face mid-trip.

Crafted from high-quality stainless steel, these parts resist corrosion from saltwater exposure and freshwater alike, extending the life of your propulsion system. Whether you're prepping for a fishing excursion, weekend cruise, or long offshore adventure, having fresh prop hardware restores confidence in your setup.

Complete Kit for Quick Replacements

  • Propeller nut: Heavy-duty design with precise threading for secure fit.
  • Washer: Thick, flat washer to distribute pressure evenly.
  • Cotter pin: High-strength pin to lock everything in place, preventing loosening from vibrations.

This all-in-one kit eliminates the hassle of sourcing individual pieces, saving you time at the dock or in the garage. It's a straightforward swap that gets you back on the water faster.

Broad Fit for Popular Outboard Brands

Engineered as a versatile replacement, this kit works seamlessly with a wide range of outboard motors from leading manufacturers. It's commonly used on models from Mercury, Johnson/Evinrude, Yamaha, Honda, and Suzuki—covering everything from 2-stroke to 4-stroke engines in various horsepower ranges.

Double-check your shaft size and threading (typically 1-inch diameter with standard prop shaft specs) to confirm fit, but its universal design makes it a go-to for most recreational and light commercial boats. Boaters often keep spares onboard for peace of mind during extended voyages.

Simple DIY Installation Steps

  1. Power off and tilt up your outboard; secure the motor if needed.
  2. Remove the old prop by straightening and pulling the cotter pin, then loosening the nut counterclockwise.
  3. Slide off the old prop, washer, and nut; inspect the shaft for damage or debris.
  4. Install the new prop onto the shaft, followed by the washer and nut—tighten clockwise to spec (usually 40-55 ft-lbs; use a torque wrench for accuracy).
  5. Insert the cotter pin through the nut and shaft hole, bending the ends securely to lock it.
  6. Lower the motor, shift into forward, and rev gently to confirm no slippage.

Pro tip: Apply a thin layer of marine grease to the shaft before reinstalling to ease future removals and reduce galling. Total time: under 15 minutes for experienced users.

Longevity and Pro Tips for Prop Hardware

Prop nuts endure constant torque, impacts from debris, and exposure to harsh marine environments. Inspect yours seasonally or after hitting underwater obstacles—look for rounded edges, pitting, or a loose cotter pin. Replacing proactively prevents prop walk or gear strain.

Pair this kit with anti-seize compound on threads for easier servicing next time. In saltwater, rinse with freshwater after use to minimize galvanic corrosion. Many anglers stock multiples for trailering mishaps or buddy loans.

Why Choose This Prop Nut Kit?

OEM-quality at aftermarket value, it matches or exceeds factory specs without the premium price tag. Stainless construction fights rust better than basic steel alternatives, and the precise machining ensures vibration-free performance. Boaters rave about its reliability in real-world tests, from bass tournaments to family outings.

Frequently Asked Questions

What sizes of propeller shafts does this kit fit?

This kit is designed for standard 1-inch propeller shafts common on most outboards from 9.9HP to 300HP. Verify your motor's shaft diameter and threading match for a perfect fit.

Is stainless steel used in this prop nut kit?

Yes, all components including the nut, washer, and cotter pin are made from marine-grade stainless steel to resist corrosion in both fresh and saltwater environments.

How often should I replace my prop nut and cotter pin?

Inspect after every 50 hours of use or following any prop strike. Replace if there's wear, bending, or loosening—typically annually for heavy use or every 2-3 years for casual boating.

Can I install this without special tools?

Basic tools like pliers, a prop wrench, and optionally a torque wrench suffice. No advanced equipment needed, making it ideal for on-water repairs.

Does it work with both 2-stroke and 4-stroke outboards?

Absolutely—its universal design accommodates prop shafts on both 2-stroke and modern 4-stroke engines across major brands.

What if my cotter pin keeps breaking?

Ensure proper torque on the nut (not over-tightened) and select the right pin size. Vibration from unbalanced props can cause breaks—balance your prop first.

Prop Nut Kit



Save $6 when you buy the Sierra 18-3715 Prop Nut Kit for only $24 from NVN Marine! Same day shipping before 3pm.

Sierra 18-3715 Prop Nut Kit Technical Specifications

Type: 

Boat Outfitting | Hull Protection

Vendor: 

Sierra Engine Parts

Weight: 

0.44 lb

Application: 

Johnson/Evinrude
OMC Sterndrive/Cobra

Contains: 

Prop Nut & Keeper 37081 (1), Cotter Pin 3741 (1), Prop Spacer 4231 (1)

OEM #: 

J/E 175266

Sierra 18-3715 Prop Nut Kit User Reviews

Sierra 18-3715 Prop Nut Kit Shipping & Return

Shipping Weight: 

0.44 lb

Box Sizes: 

2.00 (h) x 6.00 (w) x 7.00 (l)

Cubic Feet: 

84.0

Returnable: 

Yes

For detailed shipping policy please check our Shipping Policy and you can find our Return and Refund Policy here.

Sierra 18-3715 Prop Nut Kit

$24.99 $31.89 ( / )