Hydrofoil Stabilizer – Fits Outboard & Sterndrive Motors 40-300 HP (Replaces N/A)
Hydrofoil Stabilizer – Fits Outboard & Sterndrive Motors 40-300 HP (Replaces N/A) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
Orders are typically processed within 1–2 business days.
U.S. orders usually arrive within 6–15 days, depending on stock location and destination.
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Hydrofoil Stabilizer – Fits Outboard & Sterndrive Motors 40-300...
Hydrofoil Stabilizer – Fits Outboard & Sterndrive Motors 40-300 HP (Replaces N/A) is backordered and will ship as soon as it is back in stock.
Product Details
This universal Whale Tail Hydrofoil Stabilizer is designed to fit most outboard and sterndrive engines from 40–300 HP. It provides improved on-the-water performance, including quicker planing, better fuel efficiency, and reduced porpoising. Please note, it is not compatible with Mercury 40 HP 4-Stroke motors and other specific models listed in the compatibility section.
- Installation: Bolt-on installation requires drilling and uses the provided stainless steel hardware.
- Material: Constructed from durable, marine-grade UV-resistant Reinforced Nylon PA66 plastic.
- Design: Features a crescent-shaped surface with a streamlined design for improved water flow and maximum lift.
Engine & Model Compatibility
Confirm your engine model and year in the table below. This part is designed for universal fitment but has known exceptions.
Universal Fitment: The hydrofoil fits most outboard and sterndrive motors in the 40–300 HP range.
Exceptions: Note the specific models from Mercury, Volvo, Honda, and Yamaha that are confirmed to be incompatible.
| Brand | Models | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Universal | Most outboards and sterndrives | 40–300 | 2- & 4-Stroke | All | N/A | Not compatible with Mercury 40 HP 4-Stroke |
| Mercury | 4-Stroke | 40 | 4-Stroke | All | N/A | Explicitly noted as incompatible |
| Mercury | Bravo II | All | N/A | Incompatible | ||
| Mercury | Bravo III with only one anode | All | N/A | Incompatible | ||
| Volvo | With exhaust through cavitation plate | All | N/A | Incompatible | ||
| Honda | Outboards | 200+ | All | N/A | Incompatible | |
| Yamaha | Outboards | 350 | All | N/A | Incompatible |
Technical Specs
- Product Type
- Marine Hydrofoil Stabilizer (Whale Tail)
- Installation
- Bolt-on with provided hardware (drilling required)
- Material
- Marine Grade UV-Resistant Reinforced Nylon PA66 Plastic
- Color
- Silver
- Engine Type
- 2-Stroke & 4-Stroke
- Engine Size
- 40–300 HP
- Dimensions
- H: 13.5" × W: 14" (343 × 356 mm)
- Design Feature
- Crescent shaped surface with streamlined design for improved water flow
What’s in the Box
- 1 x Hydrofoil Stabilizer
- 4 x Sets of Screws and Nuts
- 1 x Drill Bit
- 1 x Installation Instructions
Installation Notes
- Confirm Fit: Before drilling, position the hydrofoil on the outboard/sterndrive's cavitation plate to ensure a proper fit and alignment.
- Mark Holes: With the hydrofoil held firmly in the desired position, use a marker to carefully mark the drilling points through the mounting holes.
- Drill Holes: Remove the hydrofoil. Using the provided drill bit, carefully drill through the cavitation plate at the marked locations.
- Apply Sealant (Recommended): Apply a marine-grade sealant around the drilled holes to prevent water ingress and corrosion.
- Mount Hydrofoil: Position the hydrofoil and insert the bolts. Secure them with the provided nuts, ensuring not to overtighten.
- Final Check: Check that the hydrofoil is secure and does not interfere with the propeller's movement or trim/tilt operation. Test on the water at low speeds first.
Troubleshooting & FAQ
How do I know if this hydrofoil will fit my specific motor?
This hydrofoil offers a universal fit for most outboard and sterndrive motors from 40 to 300 HP. However, we strongly recommend you review the compatibility table, which lists all known exceptions, such as the Mercury 40 HP 4-Stroke and certain Volvo, Honda, and Yamaha models. Do not purchase if your model is listed as incompatible.
Is drilling into my engine's cavitation plate required for installation?
Yes, installation is a bolt-on process that requires drilling four holes into the cavitation plate. All necessary mounting hardware (screws, nuts) and a drill bit are included in the package.
What specific performance improvements can I expect?
Properly installed, the hydrofoil can significantly improve your boat's performance by getting it on plane faster, reducing or eliminating porpoising (bouncing), and improving fuel efficiency at cruising speeds by allowing lower RPMs.
What is the hydrofoil made from?
It is manufactured from a high-strength, Marine Grade UV-Resistant Reinforced Nylon PA66 Plastic, designed to withstand harsh saltwater and freshwater environments without cracking or degrading.
What are the signs of incorrect installation or failure?
If installed incorrectly, you may notice no change or a negative change in performance, or unusual vibration. Signs of failure include visible cracks or the hydrofoil becoming loose. Regularly check that the mounting hardware is tight.
What if I don't see any improvement after installation?
Performance gains can vary based on boat hull, weight distribution, and engine height. Ensure the hydrofoil is mounted correctly and securely. Experimenting with your engine's trim angle can also help optimize its effect.
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.
Payment & Security
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