Firduo 75141 Underwater Thruster & Brushless Inrunner Motor 100KV 9KW for eFoil Jetboard Hydrofoil

🚤 Firduo 75141 Underwater Thruster & Brushless Inrunner Motor — 100KV / 9KW

The Firduo 75141 is a complete underwater propulsion system available as a standalone brushless inrunner motor or as a fully assembled underwater thruster. Engineered for eFoil, electric hydrofoil, jetboard, and surfboard applications, it delivers up to 55KGF thrust with a robust 18N/20P construction and full waterproof rating.

🚤 75141 Underwater Thruster 

• ✅ 55 KGF Maximum Thrust — highest thrust output in the Firduo motor lineup for demanding eFoil builds
• ✅ High-thrust propulsion kit —CNC-machined high-strength aluminum alloy propeller (JP120).Aluminum alloy low-resistance high-efficiency guide cover
  

⚡ Thrust Performance (KGF) — 16S / 60V

⚙️ 75141 Brushless Inrunner Motor

⚡ Key Features

• ✅ Fully waterproof — rated for full submersion in marine environments
• ✅ High-torque 18N/20P construction for smooth, efficient power delivery
• ✅ 55KGF maximum thrust — ideal for eFoil and jetboard propulsion
• ✅ Wide voltage range: 5S–18S (21–75V) for flexible battery compatibility
• ✅ 120℃ working temperature limit for sustained high-power operation
• ✅ 8mm gold bullet plug connectors for secure, low-resistance connections
• ✅ 1300mm extension wire — long enough for most eFoil mast configurations
• ✅ Compatible with Firduo FD75200 75V 200A VESC

📋 Motor Specifications

📦 What's in the Box

      75141-100KV Motor

• Motor × 1
• 8.0mm bullet connectors × 3
• Firduo 120A Connector × 3 (optional kit only)

      75141 Underwater Thruster

• Underwater Thruster(75141 motor + JP120 propeller + C120 Guide Cover and screw accessories) × 1
• 8.0mm bullet connectors × 3
  

🔗 Compatible Builds & Recommended Pairings

• Recommended ESC: Firduo FD75200 75V 200A Water-Cooled VESC — FOC mode, 200A continuous, full 5S–18S support, water-cooled for sustained high-power eFoil sessions
• Phase Connectors: Firduo 120A IP68 Waterproof Connector — rated for 120A continuous, IP68 sealed; included in the Motor + Connector kit variant
• Signal Connectors: Firduo 3-Core / 4-Core IP68 Waterproof Connector — for Remote receiver, sensor, temperature, and hall signal wiring
• Remote: Firduo VX5 IP68 Waterproof Remote — 5,000mAh, up to 20 hours continuous use, cruise control, PPM/UART
• Recommended Kit: Firduo eFoil Kit – 75141 Motor + 200A VESC + VX5 Remote, complete electronic system included
• Anti-Spark Switch: Firduo 200A Anti-Spark Switch — eliminates connector spark on battery connection, 12V–60V
• Applications: eFoil / electric hydrofoil, jetboard, electric surfboard, underwater thruster, ROV/AUV
• Battery: 12S–16S LiPo or Li-ion recommended for optimal power band (not included)
• Propeller: Φ12mm shaft — compatible with standard eFoil propellers; verify foil mast specifications for pitch and diameter match

🛠️ Setup Guide (Quick Start)

1. Choose your variant — Select 75141 Thruster for the complete ready-to-mount unit, Motor only if you have your own phase connectors, or Motor + Connector ×3 for the kit with 3× Firduo 120A IP68 waterproof connectors.
2. Mount the motor / thruster — Align the Φ12mm shaft with your propeller hub. Apply marine-grade thread locker to the prop nut to prevent loosening under vibration and water pressure.
3. Connect phase wires — Route the 1300mm extension wires through your mast channel. Connect the 8mm bullet plugs to the ESC phase outputs (A-B-C).
4. Connect ESC and battery — Wire the FD75200 ESC to your 12S–16S battery using a 120A–250A Connector. Install the 200A Anti-Spark Switch between battery and ESC.
5. Configure ESC via VESC Tool — Run the FOC motor detection wizard. Set motor and battery current limits. Configure throttle curve and protection thresholds before first water test.
6. Pair VX5 remote — Power on the ESC first, then the VX5. Switch to eSurf mode for water use.
7. Water test — Start at 20–30% throttle in calm water. Verify thrust direction and check for unusual vibration. Rinse with fresh water after each salt water session.

❓ FAQ

Q1: What ESC is recommended?
A: The Firduo FD75200 75V 200A VESC-compatible ESC is the ideal pairing for eFoil applications.

Q2: What battery configuration works best?
A: The motor supports 5S–18S (21–75V). For eFoil use, 12S–16S LiPo or Li-ion packs are most common.

Q3: Is this motor truly waterproof?
A: Yes — the 75141 is fully waterproof and rated for continuous submersion in fresh and salt water.

Q4: What propeller size is compatible?
A: The Φ12mm shaft is compatible with standard eFoil propellers. Check your foil mast specifications for the best match.

Q5: What is the difference between the Motor and Thruster variants?
A: The 75141 Motor is the bare inrunner motor — ideal for custom builds where you supply your own propeller and duct. The 75141 Thruster is a complete assembled unit with CNC aluminum propeller (JP120), guide cover, and all hardware included, ready to mount directly to your board or mast.