Propeller Nut Kit – Fits Mercury/Mariner 30-60 HP & Force 40-75 HP (Replaces 11-31990Q02)

$12.74 $20.00

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Propeller Nut Kit – Fits Mercury/Mariner 30-60 HP & Force 40-75 HP (Replaces 11-31990Q02) is backordered and will ship as soon as it is back in stock.

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Delivery and Shipping

Free standard shipping on all orders under 1 KG

If you have any questions, feel free to email us at info@sierramarines.com, and we’ll get back to you within 20–36 hours.

Product Details

This Propeller Nut Kit provides the essential hardware for securely mounting a rubber hub propeller on a range of Mercury/Mariner and Force outboards. It is designed for Mercury/Mariner models including 30-40 HP (1989 & newer) and 50-60 HP (1991 & newer, excluding Bigfoot), as well as Force 40-75 HP engines from select years.

This kit serves as a direct interchange for Mercury/Quicksilver OEM part numbers 11-31990Q02, 31990Q02, and 11-31990K02.

For use with rubber hub propellers only.
Mounts directly to the propeller shaft for a secure fit.
Includes the front thrust washer, tab washer, and prop nut for a complete installation.

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Brand	Part Number
Mercury/Quicksilver	11-31990Q02
Mercury/Quicksilver	31990Q02
Mercury/Quicksilver	11-31990K02

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For Mercury/Mariner models, this kit fits various 2-stroke and 4-stroke outboards from 25 HP to 70 HP, with some exclusions for Bigfoot models. Please check your specific model and year range carefully.

Brand	Model	Rated HP	Stroke	Years	OEM Part No.	Notes
Mercury/Mariner	Outboard	30	2-Stroke	1994 & Newer	11-31990Q02	-
Mercury/Mariner	Outboard	30	4-Stroke	1994–2005	11-31990Q02	-
Mercury/Mariner	Sea Pro/Marathon	30	2-Stroke	1994 & Newer	11-31990Q02	-
Mercury/Mariner	Outboard	35	2-Stroke	1984–1989	11-31990Q02	-
Mercury/Mariner	Outboard	40	2-Stroke	1989 & Newer	11-31990Q02	Excluding Bigfoot models
Mercury/Mariner	Outboard	40	4-Stroke	1989 & Newer	11-31990Q02	Excluding Bigfoot models
Mercury/Mariner	Sea Pro/Marathon	40	2-Stroke	1977 & Newer	11-31990Q02	-
Mercury/Mariner	Outboard	45	2-Stroke	1986–1989	11-31990Q02	-
Mercury/Mariner	Outboard	48	2-Stroke	All Years	11-31990Q02	Mariner models only
Mercury/Mariner	Outboard	50	2-Stroke	1991 & Newer	11-31990Q02	Excluding Bigfoot models
Mercury/Mariner	Outboard	50	4-Stroke	1991 & Newer	11-31990Q02	Excluding Bigfoot models
Mercury/Mariner	Sea Pro/Marathon	55	2-Stroke	1995 & Newer	11-31990Q02	-
Mercury/Mariner	Outboard	60	2-Stroke	1978 & Newer	11-31990Q02	Excluding Bigfoot and Sea Pro models
Mercury/Mariner	Outboard	60	4-Stroke	1978 & Newer	11-31990Q02	Excluding Bigfoot models
Mercury/Mariner	Outboard	70	2-Stroke	Through 1983	11-31990Q02	-
Mercury/Mariner	Model 402-500-700	-	2-Stroke	1977–1984	11-31990Q02	-
Mercury/Mariner	25 HP Bigfoot	25	4-Stroke	1999–2005	11-31990Q02	2006 & newer may also fit, requires verification

For Force outboards, this kit is compatible with 40 HP to 75 HP 2-stroke models from the mid-1990s.

Brand	Model	Rated HP	Stroke	Years	OEM Part No.	Notes
Force	Outboard	40	2-Stroke	1995–1998	11-31990Q02	-
Force	Outboard	50	2-Stroke	1995–1998	11-31990Q02	-
Force	Outboard	70	2-Stroke	1991–1995	11-31990Q02	-
Force	Outboard	75	2-Stroke	1996–1998	11-31990Q02	-

Technical Specs

Product Type: Propeller Nut Kit
Installation: Propeller shaft installation for rubber hub propellers
Connection: Direct mounting on propeller shaft
Housing Material: Metal (steel)
Housing Color: Silver/Metallic
Dimensions: 15.5 cm L x 10.0 cm W x 2.5 cm H
Fitting Type: Propeller shaft
Other Technical Attributes: For use with rubber hub propellers only

What’s in the Box

1 x Front thrust washer (73345A1)
1 x Tab washer (14-76281)
1 x Prop nut (11-69578Q1)

Installation Notes

Ensure the engine is off and the kill switch is disconnected. Shift the outboard into neutral for safety.
Remove the old propeller nut, tab washer, and thrust washer. A block of wood between the prop blade and anti-ventilation plate can prevent unwanted rotation.
Inspect the propeller shaft splines for damage or debris and clean them thoroughly before proceeding.
Slide the new front thrust washer (73345A1) onto the shaft, ensuring it is properly seated against the gearcase.
Install the propeller onto the splined shaft.
Place the new tab washer (14-76281) over the splines.
Thread on the new propeller nut (11-69578Q1) and tighten it to the manufacturer's recommended torque specification using a torque wrench.
Secure the nut by bending at least two tabs of the tab washer into the grooves on the nut.

Troubleshooting & FAQ

Will this fit a Mercury Bigfoot model?

No, this kit is specified to exclude Bigfoot models for Mercury/Mariner 40, 50, and 60 HP engines. Always verify your specific model requirements before ordering.

What is the purpose of the tab washer?

The tab washer is a critical locking component. After tightening the propeller nut to the correct torque, its tabs are bent against the nut to prevent it from loosening due to engine vibration during operation.

Can I reuse my old thrust washer or nut?

It is strongly recommended to replace all components in the kit simultaneously. The tab washer is a single-use item, and using a new nut and thrust washer ensures proper fit, torque, and security. Reusing old parts can compromise safety.

How do I know if my old prop nut kit is failing?

Signs of a failing kit include visible corrosion, stripped threads on the nut, a damaged tab washer, or a propeller that feels loose on the shaft even after tightening. Any rattling or unusual vibration from the propeller area warrants an immediate inspection.

OEM vs. Aftermarket?

This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.

Shipping speed & cost

We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.

Warranty & returns

Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.

Safety & Important Info

Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
This is an aftermarket replacement, not an OEM component.
Professional installation is recommended for safety and performance.

About Sea Sierra

Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.

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