The Spektrum M-SPMXMM3300 Firma 1900Kv brushless marine motor for 4S–6S deep-V boats is engineered for RC boaters who demand blistering speed, high-wattage output, and thermal resilience in offshore conditions. Designed for 36" hulls like the Pro Boat Sonicwake V2, this 4068-class inrunner motor delivers up to 3400 watts of power and supports speeds beyond 50 mph. Its 1900Kv rating ensures rapid RPM generation, while the 4-pole rotor provides torque-rich propulsion and smooth throttle response. With an integrated water cooling jacket, ball bearings front and rear, and Smart ESC compatibility, the Spektrum M-SPMXMM3300 motor offers elite performance for velocity-focused marine builds.
Key features of the Spektrum M-SPMXMM3300 motor
- 1900Kv output – delivers explosive acceleration and high RPM for deep-V and hydroplane hulls
- 3400W max power – supports extreme performance setups and competitive speed runs
- Inrunner design – compact and efficient for tight hull spaces and direct-drive systems
- Water cooling jacket – maintains thermal stability during extended high-load operation
- 5mm shaft – supports robust drivetrains and secure propeller mounting
- 5.5mm bullet connectors – enables high-current ESC integration with minimal resistance
- OEM fit – drop-in compatibility with Pro Boat Sonicwake V2 (PRB08032V2)
Why is the 1900Kv rating ideal for high-speed marine propulsion?
The Spektrum 1900Kv motor for Sonicwake V2 and hydroplane hulls offers a high-RPM profile that translates into blistering speed across open water. Its Kv rating is optimized for 4S–6S LiPo setups, enabling rapid acceleration and sustained top-end velocity. This makes it ideal for deep-V hulls and hydroplanes where throttle responsiveness and speed are critical. Whether you're racing or pushing performance boundaries, the motor’s Kv output ensures consistent propulsion and control.
How does the inrunner design benefit tight hull configurations?
The Spektrum M-SPMXMM3300 4-pole inrunner motor with water cooling jacket features a compact rotor configuration that fits easily into confined hull spaces. The inrunner format supports direct-drive systems and high RPM operation, making it ideal for speed-focused builds. Combined with the 4-pole rotor, the motor delivers smooth throttle response and torque-rich acceleration, even under aggressive launch conditions. Its efficient layout also reduces drag and vibration, enhancing overall handling and durability.
What role does the water cooling jacket play in thermal management?
The Spektrum M-SPMXMM3300 with 3400W output and Smart ESC compatibility includes an integrated water cooling jacket that actively dissipates heat during operation. This feature is essential for marine environments where continuous throttle use can lead to thermal buildup. By maintaining optimal operating temperatures, the cooling system protects internal components and preserves consistent performance. For boaters pushing their setups to the limit, this thermal management system ensures that the motor remains cool, efficient, and responsive throughout the run.
How does Smart ESC compatibility enhance system performance?
The Spektrum Firma motor with ball bearings and high-RPM inrunner design is designed to pair seamlessly with Firma Smart Marine ESCs, including the 160A variant. This compatibility enables telemetry feedback, adaptive timing, and simplified setup, enhancing system awareness and control. The motor’s electrical specifications align with Smart ESC parameters, ensuring safe current handling and efficient power delivery. For users building Smart Technology-equipped boats, this integration offers a reliable and performance-matched solution.
Why choose the Spektrum M-SPMXMM3300 motor for your next RC boat build?
The Spektrum M-SPMXMM3300 Firma 1900Kv brushless marine motor for 4S–6S deep-V boats combines high-RPM output, thermal stability, and installation simplicity in a single, race-ready package. Its 4-pole inrunner design supports aggressive launches, while the water cooling jacket ensures consistent performance during extended runs. With OEM compatibility for the Sonicwake V2 and support for Smart ESCs, this motor offers plug-and-play convenience and elite propulsion. For RC boaters seeking the affordable Spektrum 4068 1900Kv motor for aggressive offshore performance setups, this model delivers unmatched value and reliability. Buy Spektrum M-SPMXMM3300 motor for high-speed marine builds with 4S–6S LiPo.
Overview
The PRB Firma 1900KV Brushless Marine Motor (M-SPMXMM3300) is a high-performance inrunner motor engineered for serious RC boaters who demand blistering speed, exceptional power delivery, and thermal resilience during extended operations on open water. This brushless RC marine motor is purpose-built for surface RC boats running 4–6S LiPo battery configurations, making it an ideal choice for deep-V hulls, hydroplanes, and competitive speed setups. Whether you're a seasoned racer looking to push performance boundaries or an enthusiast seeking a reliable upgrade for your existing RC boat, the Firma 1900KV delivers the explosive acceleration and sustained velocity needed to dominate on the water.
Designed specifically for 36-inch hulls such as the Pro Boat Sonicwake V2, this brushless marine motor represents the pinnacle of high-speed marine propulsion technology. With its robust 1900Kv rating, the motor generates rapid RPM output that translates into speeds beyond 50 mph in optimal conditions. The 4068-class inrunner design combines compact efficiency with serious power output, making it perfect for tight hull spaces whilst maintaining direct-drive compatibility. This is a motor for users who understand that marine RC performance isn't just about raw power—it's about reliability, consistency, and the ability to maintain peak performance during demanding high-load operations.
If you're shopping for a brushless RC motor UK retailers stock, you'll find the Firma 1900KV stands out from the crowd. Its integration of water cooling technology, dual ball bearing support, and Smart ESC compatibility ensures this motor will serve as the centrepiece of a high-performance marine build. RC Model Shop stocks this premium Spektrum product for customers throughout the United Kingdom, and we're proud to offer it at competitive pricing with expert technical support.
Key Features
- 1900Kv High-RPM Rating — The 1900Kv specification is optimised for 4S–6S LiPo battery setups, delivering explosive acceleration and exceptional top-end velocity across open water. This high Kv rating ensures rapid RPM generation that translates directly into speed, making it ideal for competitive racing and performance-focused builds where throttle responsiveness and sustained acceleration are critical factors.
- 3400 Watts Maximum Power Output — This motor delivers up to 3400 watts of continuous power, providing the raw energy needed for extreme performance setups and competitive speed runs. The high wattage output ensures your boat has the energy reserves needed for aggressive acceleration, sustained high-speed runs, and the ability to maintain performance even under heavy load conditions.
- 4-Pole Inrunner Design — The 4-pole rotor configuration provides torque-rich propulsion and smooth throttle response, whilst the inrunner design itself is compact and efficient for tight hull spaces. This engineering approach allows for direct-drive systems whilst maintaining the efficiency and performance characteristics that serious RC boaters demand from their equipment.
- Integrated Water Cooling Jacket — The motor features a dedicated water cooling jacket that maintains thermal stability during extended high-load operation. This cooling system is essential for maintaining peak performance during long racing sessions or sustained high-speed runs, preventing thermal throttling and ensuring consistent power delivery throughout your boating session.
- Dual Ball Bearing Support — Front and rear ball bearings provide smooth rotation, reduced friction, and enhanced durability. This bearing-supported construction ensures the motor can handle the rigorous demands of high-performance marine use, delivering reliable operation session after session.
- 5mm Solid Steel Shaft — The robust 5mm shaft diameter supports secure propeller mounting and accommodates demanding drivetrain configurations. This solid construction minimises flex and vibration, ensuring reliable torque transfer and consistent performance during aggressive throttle inputs.
- 5.5mm Bullet Connectors — High-quality 5.5mm bullet connectors enable seamless integration with modern brushless ESCs whilst minimising electrical resistance. These connectors support the full 140A continuous current rating and facilitate quick, reliable connections for maintenance and upgrades.
- Smart ESC Compatibility — The motor is fully compatible with Smart ESC systems, enabling advanced telemetry, programmable features, and optimised power delivery. This compatibility allows you to monitor motor performance in real-time and adjust settings to suit your specific boating conditions and driving style.
- OEM Fit for Pro Boat Sonicwake V2 — The motor is engineered as a drop-in replacement for the Pro Boat Sonicwake V2 (PRB08032V2), ensuring perfect compatibility and seamless integration into this premium 36-inch deep-V platform without modification.
- No Adjustable Timing — The motor features fixed timing, which simplifies setup and ensures consistent, predictable performance characteristics. This straightforward approach is ideal for users who want to focus on boating rather than complex motor configuration.
Technical Performance
The Spektrum M-SPMXMM3300 Firma 1900KV brushless marine motor represents elite engineering for high-speed RC boating. At 51mm outer diameter and 86mm total length, this motor provides a compact yet powerful solution for demanding marine applications. Weighing just 392 grams (13.8 ounces), it delivers an exceptional power-to-weight ratio that translates into responsive acceleration and nimble handling characteristics. The motor's four-pole inrunner configuration generates 3400 watts of maximum power whilst maintaining thermal stability through its integrated water cooling jacket—essential technology for extended operating sessions where thermal management directly impacts sustained performance. The 1900Kv rating, combined with 4–6S LiPo compatibility, creates an optimal power band for deep-V hulls and hydroplane configurations, where rapid RPM generation directly correlates with top-end speed potential. With a maximum continuous current rating of 140A, this motor demands a correspondingly rated brushless ESC, but the payoff is consistent, reliable power delivery that won't sag under load. The 5mm shaft accepts standard propeller hardware, whilst the 5.5mm bullet connectors provide high-amperage capacity with minimal resistive losses. Ball bearing support front and rear ensures smooth operation and extended service life, even under the demanding conditions of high-speed marine racing where vibration and lateral loads are constantly at work. This is a purpose-built motor for users who understand that performance marine RC requires more than just specifications on paper—it requires engineering excellence, proven reliability, and components designed specifically for the unique challenges of water-based operation.
What's in the Box
- PRB Firma 1900KV Brushless Marine Motor (M-SPMXMM3300)
- Motor documentation and technical information
What You Need to Complete
- Brushless Electronic Speed Controller (ESC) rated for minimum 140A continuous current
- 4–6S LiPo battery pack (3S minimum, 6S maximum)
- Battery charger compatible with LiPo chemistry
- Suitable RC boat with compatible hull and drivetrain (Pro Boat Sonicwake V2 recommended)
- Propeller rated for high-speed marine use
- Bearing grease and general maintenance supplies
Frequently Asked Questions
- Is the PRB Firma 1900KV motor suitable for my 36-inch deep-V RC boat? — Yes, this motor is specifically engineered for 36-inch deep-V hulls such as the Pro Boat Sonicwake V2, where its 1900Kv rating and 3400-watt output provide optimal performance. The inrunner design ensures compatibility with direct-drive systems common in high-performance marine setups, and the 5mm shaft accepts standard marine propeller hardware without modification.
- What battery configuration does this motor require? — The Firma 1900KV is rated for 4–6S LiPo battery packs, meaning it can operate safely on battery configurations from 14.8 volts (4S) up to 22.2 volts (6S). A 6S LiPo configuration will deliver maximum RPM and power output, whilst 4S configurations provide a more conservative operating envelope. Always ensure your ESC is rated for your chosen battery voltage to maintain safe operation.
- What ESC rating do I need for this motor? — Due to the motor's 140A maximum continuous current rating, you must use an Electronic Speed Controller rated for at least 140A continuous output. Using an undercurrent-rated ESC risks damaging the controller during high-throttle operations. Many users pair this motor with 150A–200A brushless ESCs to ensure adequate headroom for thermal management and sustained performance.
- Will this motor fit my existing RC boat setup? — Compatibility depends on your specific boat model. This motor is confirmed as an OEM-fit upgrade for the Pro Boat Sonicwake V2 (PRB08032V2). For other boats, you'll need to verify that the 5mm shaft diameter, 51mm outer diameter, and 86mm length align with your hull's motor compartment and drivetrain. Contact RC Model Shop if you need specific compatibility advice for your boat model.
- How does the integrated water cooling system work? — The motor features a water cooling jacket that allows lake or sea water to circulate around the motor body during operation. This cooling system maintains optimal thermal conditions during extended high-speed runs, preventing thermal throttling and ensuring consistent power delivery. Ensure your boat's cooling system is properly connected and functioning before extended use in hot conditions.
- What's the difference between this 1900Kv motor and lower Kv alternatives? — The 1900Kv rating generates higher RPM per volt compared to lower Kv motors (such as 1500Kv options), resulting in greater top-end speed but potentially lower torque at lower throttle positions. The 1900Kv is optimised for speed-focused applications where maximum RPM and velocity are priorities, making it ideal for competitive racing and deep-V designs where speed is paramount.
- Is this motor suitable for beginners in RC boating? — Whilst this is an excellent motor from a technical standpoint, it's best suited for intermediate to advanced RC boaters who understand brushless motor systems, LiPo battery management, and high-performance ESC configuration. The 140A current requirement and 4–6S voltage range demand proper equipment setup and responsible operation. Beginners should consult experienced RC boaters or RC Model Shop staff before purchasing this motor.
- How much thrust does this motor generate? — The source specifications provide power output (3400 watts) and electrical specifications, but don't specify thrust in newtons or pounds-force. Actual thrust depends heavily on propeller selection, hull design, and water conditions. We recommend contacting Spektrum technical support or consulting RC boating forums for thrust estimates with specific propeller combinations.
Why Buy from RC Model Shop?
RC Model Shop is a trusted UK RC retailer and authorised dealer for all the brands we stock, including Traxxas, ARRMA, Losi, FTX, Hobbywing, Spektrum and more. Based in Walsall, we have a physical store where customers are welcome to come in, view products and purchase in store. Whether you are a seasoned competitor, a weekend basher, or just discovering the world of RC for the first time, our team of experienced RC enthusiasts is here to help you find the perfect setup and provide ongoing support. Order the PRB Firma 1900KV Brushless Marine Motor M-SPMXMM3300 today with confidence, knowing you are buying from an authorised retailer with genuine products, expert knowledge and a commitment to customer satisfaction. Shop online or visit us in Walsall — we look forward to helping you get the most out of your RC experience.
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