Whale Tail Hydrofoil Stabilizer – Fits Outboard Motors & Stern Drives 40-300 HP
This hydrofoil stabilizer is engineered to enhance the performance of a wide range of outboard motors and stern drives from 40 to 300 HP. It provides improved stability, reduced cavitation, faster planing, and better fuel efficiency for a smoother ride.
It is compatible with most major outboard and stern drive brands, including Mercury, Yamaha, Johnson, Evinrude, Honda, and Suzuki. This is a direct aftermarket replacement for NorthBoat FO2003, SeaSierra 300, QuickMarine Whale Tail Silver, and Marine Whale Tail Silver.
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Installation: Bolts directly to the cavitation plate. Drilling is required.
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Material: Constructed from UV-resistant, marine-grade reinforced Nylon PA66 plastic.
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Engine Compatibility: Fits most 2-stroke and 4-stroke engines between 40-300 HP (see exceptions below).
Compatible Engine Models
Confirm your engine model/year in the list below. For Mercury owners, here’s a guide to help you identify your engine’s serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.
For Johnson/Evinrude owners, here’s a guide to help you identify your engine’s serial/model: Johnson Serial Number Guide.
For Yamaha owners, here’s a guide to help you identify your engine’s serial/model: Yamaha Serial Number Guide. You can also review exploded diagrams to verify part numbers: Yamaha Parts Diagrams & Catalog.
For Suzuki owners, You can review exploded diagrams here to verify part numbers: Suzuki Parts Diagrams & Catalog.
Compatible With:
- Most outboard motors and stern drives from 40-300 HP
- Yamaha, Mercury, Johnson, Evinrude, Honda, and Suzuki engines within the 40-300 HP range
Not Compatible With:
- Mercury 4-Stroke 40 HP, 50 HP, 60 HP
- Mercury Bravo II
- Mercury Bravo III with only one anode on the bottom of the cavitation plate (rare configuration)
- Volvo models with exhaust through the cavitation plate
- Honda 200 HP and higher
- Yamaha 350 HP
Technical Specifications
| Specification |
Value |
| Product Type |
Hydrofoil Stabilizer (Whale Tail) |
| Installation |
Bolted to cavitation plate; drilling required |
| Material |
Marine Grade Reinforced Nylon PA66 Plastic (UV-Resistant) |
| Color |
Silver |
| Dimensions |
H: 13.5 inches (343mm), W: 14 inches (356mm) |
| Weight |
2.94 lb (1.33 kg) |
| Mounting Type |
Outboard/Sterndrive mount |
| Engine Compatibility |
40-300 HP outboards and stern drives |
| Engine Type |
2-Stroke & 4-Stroke |
Performance Benefits
- Improves handling and provides better maneuverability
- Enhances thrust and control for better performance
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Cuts planing time and keeps the boat on plane at lower speeds
- Saves fuel by improving overall engine efficiency
- Eliminates or significantly reduces porpoising and cavitation
- Provides a smoother, more stable ride in various water conditions
Package Contents
- 1 x Hydrofoil Stabilizer Board
- 4 x Sets of Stainless Steel Screws and Nuts
- 1 x 6.5mm Drill Bit included for installation
- 1 x Installation Instruction Sheet
Installation Guide
- Center the hydrofoil on top of the engine's cavitation plate. Ensure it is positioned correctly before marking.
- Mark the four hole locations on the cavitation plate using the hydrofoil as a template.
- Carefully drill the four marked holes using the included 6.5mm drill bit.
- Place the hydrofoil back onto the cavitation plate, aligning the holes.
- Insert the stainless steel bolts from the top and secure them with the nuts from the bottom.
- Tighten all four sets of screws and nuts firmly. Check for a secure fit before operating the boat.
Troubleshooting & FAQ
Q: How do I confirm this hydrofoil will fit my specific engine model?
A: This hydrofoil is designed for most outboard and sterndrive engines from 40-300 HP. Please carefully review the "Not Compatible With" list to check for specific exceptions, such as certain Mercury 4-stroke models, Mercury Bravo II/III drives, and high-horsepower Honda/Yamaha engines. Always visually compare it to your engine's cavitation plate to ensure a proper fit.
Q: What is the main benefit of installing a hydrofoil?
A: The primary benefits are improved performance and stability. It helps your boat get on plane faster, stay on plane at lower speeds (improving fuel economy), and reduces common issues like porpoising (bow bouncing) and cavitation (propeller ventilation).
Q: Does installation require any special tools?
A: The package includes all necessary mounting hardware (stainless steel screws and nuts) and a 6.5mm drill bit. You will need a drill to complete the installation. Professional installation is always recommended for safety.
Q: OEM vs. Aftermarket?
A: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.
Q: How fast do you ship and how much does it cost?
A: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.
Q: What is your warranty and return policy?
A: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.
Important Notes
- Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
- This product is an aftermarket replacement part and is not an OEM component.
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Professional installation is recommended to ensure safety and optimal performance.
Why Choose JLM MARINE?
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Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
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Fast Global Shipping: Free delivery worldwide in 5–15 days.
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Direct from Manufacturer: Competitive pricing without compromising quality.