Sierra 18-3701 Prop Nut Kit, Replaces Mercury/Mercruiser 11-52707A1, 11-52707Q1, Fits 150 HP Outboards

The Sierra 18-3701 Prop Nut Kit is a replacement propeller nut kit built to secure the propeller assembly on compatible 150 HP outboards. The kit provides the prop nut and tab washer needed to properly torque and lock the propeller in place on the propeller shaft, restoring a secure, vibration-resistant fit after servicing or replacing a propeller. It is manufactured from alloy steel with a machined finish and zinc plating for corrosion resistance in the marine environment.

This kit directly replaces Mercury/Mercruiser part numbers 11-52707A1 and 11-52707Q1, making it a straightforward drop-in replacement when the original prop nut or tab washer is worn, corroded, or lost during a propeller change. Sierra 18-3701 is confirmed for 150 HP applications for the 1990 model year (B, C, D models) and the 1991 model year (all models). Always confirm the part number stamped on your existing hardware or consult your engine's serial number range before ordering to ensure correct fitment.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-3701
• Product Type: Prop Nut Kit
• Material: Alloy Steel
• Finish: Machined, Zinc Plated
• Thread Size: 1/2 inch
• Item Dimensions: 0.39 x 0.39 x 0.39 inches
• Weight: 0.19 pounds
• Number of Items: 1
• UPC: 030999256195
• OEM Cross Reference: 11-52707A1, 11-52707Q1

Fitment

• 150 HP, 1990 model year, B, C, D models
• 150 HP, 1991 model year, all models

Replaces (OEM)

• Mercury/Mercruiser 11-52707A1
• Mercury/Mercruiser 11-52707Q1

Frequently Asked Questions

What does the Sierra 18-3701 Prop Nut Kit include? The Sierra 18-3701 kit includes the prop nut and tab washer needed to secure a compatible propeller onto the propeller shaft.

What OEM part numbers does the 18-3701 replace? It replaces Mercury/Mercruiser part numbers 11-52707A1 and 11-52707Q1.

What engines does Sierra 18-3701 fit? It fits 150 HP applications for the 1990 model year (B, C, D models) and the 1991 model year (all models).

What material is the 18-3701 prop nut kit made from? The kit is made from alloy steel with a machined finish and zinc plating for corrosion resistance.

What is the thread size on the Sierra 18-3701 prop nut? The Sierra 18-3701 prop nut uses a 1/2 inch thread size.

How much does the Sierra 18-3701 Prop Nut Kit weigh? The kit weighs 0.19 pounds.

Is the Sierra 18-3701 a genuine OEM part or aftermarket? Sierra 18-3701 is an aftermarket replacement kit manufactured to replace Mercury/Mercruiser OEM parts 11-52707A1 and 11-52707Q1.

Do I need to replace the tab washer every time I remove the propeller? The Sierra 18-3701 kit includes a tab washer along with the prop nut so both wear items are available together when servicing the propeller.

How many prop nuts and washers come in one 18-3701 kit? One 18-3701 kit contains a single set: one prop nut and one tab washer.

Will Sierra 18-3701 fit engines outside the listed 1990 and 1991 model years? Fitment for the 18-3701 is confirmed for 150 HP, 1990 (B, C, D models) and 1991 (all models); confirm your engine's model and serial number before ordering.