Hydrofoil Stabilizer – Fits Outboard/Stern Drive Motors 40-350 HP (Replaces PMJR71B)

Hydrofoil Stabilizer – Fits Outboard/Stern Drive Motors 40-350 HP (Replaces PMJR71B)

This hydrofoil stabilizer enhances boat performance by improving handling, increasing thrust, and reducing the time it takes to get on plane. It also helps keep the boat on plane at lower speeds, contributing to better fuel efficiency. It is designed for a universal fit on most outboard and stern drive motors in the 40-350 HP range.

Directly replaces aftermarket parts: SeaSierra PMJR71B and XRmarine Sport-300.

• Installation Type: Bolt-on (drilling is required).
• Construction: Made from high-strength, UV-resistant marine-grade nylon PA66 plastic.
• Hardware Included: Comes with stainless steel mounting hardware and a drill bit.

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across other aftermarket brands.

Compatible Engine Models

Confirm your engine model/year in the table 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/Evinrude 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.

Note: Not compatible with Volvo Ocean Series XDP stern drives.

Technical Specifications

Package Contents

• 1 × Hydrofoil Stabilizer
• 4 × Sets of Stainless Steel Screws and Nuts
• 1 × 6.5mm Drill Bit
• 1 × Installation Instructions

Installation Guide

1. Ensure the engine is off and the boat is securely trailered or docked.
2. Position the hydrofoil onto the cavitation plate of the lower unit. Center it side-to-side and place it as far back as possible without interfering with the propeller.
3. Use a pencil or marker to mark the drilling locations on the cavitation plate through the mounting holes of the hydrofoil.
4. Remove the hydrofoil and carefully drill the four marked holes using the included 6.5mm drill bit.
5. Place the hydrofoil back onto the cavitation plate, aligning it with the newly drilled holes.
6. Insert the stainless steel screws from the top and secure them from the bottom with the provided nuts.
7. Tighten all nuts securely. It is recommended to check and re-tighten the hardware after the first few hours of use.

Troubleshooting & FAQ

Q: How do I know if this hydrofoil will fit my motor?
A: This hydrofoil features a universal design for most outboard and stern drive motors from 40 to 350 HP. The critical factor is ensuring it can be mounted securely to your engine's cavitation plate. Please review the dimensions and compatibility table before purchasing.

Q: Do I have to drill holes in my engine's cavitation plate?
A: Yes, a bolt-on installation is required to ensure a secure fit for safe and effective performance. This involves drilling four holes in the cavitation plate. The kit includes all necessary mounting hardware and a drill bit to complete the job.

Q: What performance benefits can I realistically expect?
A: A properly installed hydrofoil helps your boat get on plane faster and stay on plane at lower speeds. This reduces bow rise, porpoising, and cavitation, often leading to improved handling, stability, and fuel economy.

Q: The compatibility notes for my Volvo Penta drive mention I need different hardware. Is it included?
A: For certain Volvo Penta models (including SX-A, DPS, DPR series), you will need longer bolts and 1" fender washers for a proper fit. Please be aware that this specific hardware is not included in the standard package.

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.
• Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.