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Hydrofoil Stabilizer – Fits Outboard Motors 40-300 HP (Replaces SeaSierra FO2003)

Sale price $63.60 Regular price $101.00
Shipping calculated at checkout.

Hydrofoil Stabilizer – Fits Outboard Motors 40-300 HP (Replaces SeaSierra FO2003) is backordered and will ship as soon as it is back in stock.


Worry-free returns

You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).

You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).

If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.

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 Marine Whale Tail Hydrofoil Stabilizer is designed to enhance performance for most outboard and stern drive motors from 40 to 300 HP. By providing lift and stability, it improves handling, reduces planing time, and eliminates common issues like porpoising and cavitation, ensuring a smoother and more efficient ride.

This part serves as a direct replacement for interchange numbers SeaSierra FO2003, NorthBoat FO2003, SupremeMarine FO2003, and UANOFCN FO2003.

  • Installation involves drilling and mounting directly onto the anti-cavitation plate.
  • Constructed from high-strength, reinforced Nylon PA66 marine-grade plastic for durability.
  • Comes as a complete kit with stainless steel mounting hardware and a drill bit.

Part Number Matrix

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

Brand Part Number
SeaSierra FO2003
NorthBoat FO2003
SupremeMarine FO2003
UANOFCN FO2003

Engine & Model Compatibility

Confirm your engine model and year in the tables below. This hydrofoil fits a wide range of outboard motors from 40-300 HP, with some specific exceptions noted in the incompatible models list.

Brand Model Rated HP Stroke Years OEM Part No. Notes
Mercury Various 40–300 HP 2-Stroke & 4-Stroke All FO2003 Except Mercury 4-Stroke 40, 50, 60 HP
Yamaha Various 40–300 HP 2-Stroke & 4-Stroke All FO2003 Except 350 HP models
Johnson Various 40–300 HP 2-Stroke & 4-Stroke All FO2003
Evinrude Various 40–300 HP 2-Stroke & 4-Stroke All FO2003
Honda Various 40–300 HP 2-Stroke & 4-Stroke All FO2003 Except 200 HP and higher
Suzuki Various 40–300 HP 2-Stroke & 4-Stroke All FO2003
Tohatsu Various 40–300 HP 2-Stroke & 4-Stroke All FO2003

Please review the specific exclusions below to ensure compatibility.

Brand Model Rated HP Stroke Years Notes
Mercury Various 40, 50, 60 HP 4-Stroke All Incompatible
Mercury Bravo II Various Various All Incompatible with exhaust through cavitation plate
Mercury Bravo III Various Various All Incompatible with only one anode on bottom of cavitation plate (rare)
Yamaha Various 350 HP 4-Stroke All Incompatible
Honda Various 200+ HP 4-Stroke All Incompatible
Volvo Various Various Various All Incompatible with exhaust through cavitation plate

Technical Specs

Product Type
Marine Hydrofoil Stabilizer
Installation
Anti-cavitation plate mount (requires drilling)
Connection
4 mounting bolts with included hardware
Housing Material
Reinforced Nylon PA66 Marine Grade Plastic
Housing Color
Available in Blue, Red, or Silver
Package Dimensions
17.5 x 15 x 3 inches
Weight
1.72 kg (3.79 lbs)
Fitting Type
Anti-cavitation plate direct mount
Hardware
Stainless steel mounting hardware included
Warranty
90 Days (manufacturer dependent)
Other Technical Attributes
Crescent-shaped surface channels water for improved thrust; eliminates porpoising, cavitation, and chine walking

What’s in the Box

  • 1 x Hydrofoil Stabilizer (FO2003)
  • 4 x Set of Stainless Steel Screws and Nuts
  • 1 x Drill Bit (6.5mm)
  • 1 x Installation Instruction

Installation Notes

  1. Center the hydrofoil on the motor's anti-cavitation plate. Ensure it does not interfere with the propeller or steering.
  2. Mark the positions for the four mounting holes through the hydrofoil onto the plate.
  3. Remove the hydrofoil and carefully drill the marked holes using the included 6.5mm drill bit.
  4. Place the hydrofoil back onto the plate, aligning the holes.
  5. Insert the stainless steel bolts from the top and secure them with the nuts from the bottom.
  6. Tighten all four bolts firmly and evenly. Check for a secure fit before operating the boat.

Troubleshooting & FAQ

How do I know if this hydrofoil will fit my motor?

This stabilizer is designed for a universal fit on most 40-300 HP outboard and sterndrive motors. Please review the compatibility tables and, specifically, the list of known incompatible models. If your engine is listed as incompatible, this part will not fit.

Is drilling required for installation?

Yes, installation requires drilling four holes into your motor's anti-cavitation plate. The package includes a drill bit and all necessary stainless steel mounting hardware.

What benefits can I expect after installation?

The hydrofoil improves performance by getting the boat on plane faster, increasing stability at low speeds, reducing fuel consumption, and eliminating common issues like porpoising, cavitation, and chine walking for a smoother ride.

Will this stop my boat from porpoising?

Yes, one of the primary functions of this hydrofoil is to reduce or completely eliminate porpoising by providing stabilizing lift at the stern of the boat.

My motor is a Mercury 60 HP 4-Stroke. Will this fit?

No, per the incompatibility list, this hydrofoil is not compatible with Mercury 4-stroke motors rated at 40, 50, or 60 HP.

How does this aftermarket part compare to an original?

This hydrofoil is an aftermarket replacement for parts like the NorthBoat FO2003. It is designed to meet or exceed original specifications for fit and function, using high-quality marine-grade materials.

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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