Hydrofoil Stabilizer Fins for Outboard Motors Up to 50 HP (4–50 HP)
Hydrofoil Stabilizer Fins for Outboard Motors Up to 50 HP (4–50 HP) 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.
International delivery times may vary due to customs processing.
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Hydrofoil Stabilizer Fins for Outboard Motors Up to 50 HP (4–50 HP)
Hydrofoil Stabilizer Fins for Outboard Motors Up to 50 HP (4–50 HP) is backordered and will ship as soon as it is back in stock.
Product Details
These Hydrofoil Stabilizer Fins are designed for outboard motors rated from 4 to 50 HP. When correctly fitted to a compatible anti-ventilation plate, hydrofoils can help a boat get on plane sooner, remain on plane at lower speeds, and improve overall stability and tracking. The two-piece design allows the left and right foils to work independently, helping absorb impact and contributing to a smoother ride.
The fins are suitable for many small and mid-size outboard applications, including selected Mercury, Mariner, Yamaha, Johnson, Evinrude, Honda, Tohatsu, and Suzuki motors. Compatibility depends on the engine configuration, anti-ventilation plate dimensions, available mounting area, and installation clearance.
- Designed for outboard motors rated from 4 to 50 HP.
- Two-piece left-and-right foil design for independent movement.
- Mounts to the anti-ventilation plate with drilled mounting holes.
- Constructed from high-strength black plastic for marine use.
- Includes stainless steel mounting hardware listed below.
Part Number Matrix
The references below are aftermarket cross-references for similar hydrofoil applications. Confirm dimensions and mounting requirements before ordering; they are not a statement of OEM manufacture or universal interchangeability.
| Brand | Part Number | Notes |
|---|---|---|
| Five Oceans | FO-4470 | Aftermarket cross-reference for similar applications |
| SE Sport | 300 | Similar hydrofoil application; verify dimensions before installation |
Engine & Model Compatibility
This product is intended for compatible outboard motors in the 4–50 HP range. The brand and model examples below are application categories rather than confirmation of every engine in each range. Always compare the anti-ventilation plate and mounting area with the product dimensions before installation.
| Brand | Model | Rated HP | Stroke |
|---|---|---|---|
| Mercury | Selected models | 4–50 HP | 2- and 4-stroke applications |
| Mariner | Selected models | 4–50 HP | 2- and 4-stroke applications |
| Yamaha | Selected models | 4–50 HP | 2- and 4-stroke applications |
| Johnson | Selected models | 4–50 HP | 2- and 4-stroke applications |
| Evinrude | Selected models | 4–50 HP | 2- and 4-stroke applications |
| Honda | Selected models | 4–50 HP | 2- and 4-stroke applications |
| Tohatsu | Selected models | 4–50 HP | 2- and 4-stroke applications |
| Suzuki | Selected models | 4–50 HP | 2- and 4-stroke applications |
Technical Specs
- Product Type
- Outboard engine hydrofoil stabilizer fins
- Recommended Engine Range
- 4–50 HP
- Installation
- Bolt-on installation; drilling required
- Connection
- Mounts to the anti-ventilation plate, also called the cavitation plate
- Mounting Pattern
- Four mounting holes
- Material
- High-strength black plastic
- Color
- Black
- Approximate Fin Dimensions
- 180 mm × 180 mm per fin (approximately 7.1 in × 7.1 in)
- Configuration
- Two-piece left-and-right foil set
- Design Feature
- Each foil is designed to flex independently to help absorb shock
What’s in the Box
- 1 × left-and-right hydrofoil fin set
- 4 × stainless steel screws
- 4 × washers
- 4 × pressure nuts
Installation Notes
- Confirm that the anti-ventilation plate has enough flat mounting area and that the fin dimensions will clear the propeller, gearcase, trim system, and other components.
- Center the two hydrofoil pieces on the anti-ventilation plate.
- Mark the four mounting-hole positions and check that no cables, structures, or other components are behind the drilling locations.
- Carefully drill the four marked holes using an appropriately sized drill bit and suitable marine installation practices.
- Place the fins on the plate and align the holes.
- Insert the stainless steel screws with washers from the top and secure them from below with the pressure nuts.
- Tighten the hardware evenly and securely without overtightening. Inspect the installation before operating the vessel.
Troubleshooting & FAQ
Will these fins fit my specific outboard motor?
They are designed for compatible outboard motors rated from 4 to 50 HP, but the stated horsepower range alone does not confirm fitment. Measure the anti-ventilation plate, compare it with the approximate 180 mm × 180 mm fin dimensions, and verify that there is sufficient clearance for drilling and operation.
What performance benefits can I expect?
Hydrofoils may help reduce the time required to get on plane, maintain plane at lower speeds, and improve stability and tracking. Actual results vary with hull design, boat weight, load distribution, engine mounting height, trim, and operating conditions.
Are these the same product as the Five Oceans FO-4470 or SE Sport 300?
No. Those numbers are provided as aftermarket cross-references for similar applications. The products are not claimed to be manufactured by those brands, and dimensions and mounting requirements should be verified before treating any reference as interchangeable.
Does installation require drilling?
Yes. Installation requires four holes to be drilled through the anti-ventilation plate. If you are not experienced with marine hardware installation, have the work completed or checked by a qualified marine technician.
How often should I check the mounting hardware?
Inspect the screws, washers, and pressure nuts during regular pre-launch checks and periodically during the boating season. Stop using the boat if the fins or hardware become loose, damaged, or misaligned.
Is this an OEM component?
No. This is an aftermarket hydrofoil stabilizer fin set. It is not represented as an OEM component for any particular outboard manufacturer.
What warranty and return terms apply?
Warranty coverage and return eligibility are governed by the seller’s current policies. Contact support before installation if the product arrives damaged or appears unsuitable for your application.
Safety & Important Info
- Verify the fin dimensions, anti-ventilation plate layout, available drilling area, and operating clearance before purchase and installation.
- Do not rely on horsepower, brand, or model name alone to determine compatibility.
- Inspect all mounting hardware after installation and before operation.
- This is an aftermarket replacement product, not an OEM component.
- Professional installation is recommended when drilling the anti-ventilation plate or when fitment is uncertain.
About Sea Sierra
- Marine-Focused Products — We supply replacement and performance components for a range of boating applications.
- Application-Focused Information — Product specifications and installation guidance are provided to help customers compare fitment requirements.
- Customer Support — Contact our support team with your engine details and installation questions before fitting the product.
Payment & Security
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