HOBBYWING EZRUN 4278SD 2250KV BLACK G2R 1/8TH SENSORED MOTOR HW30402141

Overview

The Hobbywing EZRUN 4278SD 2250KV BLACK G2R is a professional-grade brushless motor designed for 1/8th scale RC buggies and monster trucks. This sensored motor brings cutting-edge engineering to competitive and recreational RC driving in the UK, offering exceptional linear power delivery and smooth throttle response that rivals much more expensive alternatives. Whether you're a dedicated RC enthusiast looking to upgrade your existing setup or a serious racer seeking maximum performance, this motor delivers the reliability and power you need to dominate on any terrain.

Built by Hobbywing, one of the world's most recognised manufacturers of brushless RC motors and electronic speed controllers, the EZRUN 4278SD represents the latest generation of motor technology. The G2R designation signifies second-generation refined engineering, incorporating years of feedback from professional racers and weekend bashers alike. This motor is specifically engineered to work seamlessly with the Hobbywing EZRUN MAX8 G2S ESC, creating a perfectly matched power system that delivers optimal performance characteristics you simply cannot achieve with mismatched components.

The 2250KV rating makes this motor ideal for 1/8th scale applications running 3-6S LiPo batteries, giving you flexibility in your power setup whilst maintaining consistent, predictable performance across different battery configurations. The sensored design ensures smooth, linear acceleration from a standstill, eliminating the cogging and hesitation you might experience with sensorless alternatives, making this an excellent choice for both track racing and off-road bashing across the UK.

Key Features

• Sensored Brushless Design — The integrated sensor system provides real-time motor feedback to the ESC, enabling smooth, linear throttle response and eliminating cogging noise. This means you get predictable power delivery whether you're launching from a standstill or accelerating at speed, giving you superior control and consistency during competitive racing or recreational driving.
• Perfect Compatibility with EZRUN MAX8 G2S ESC — This motor is engineered to pair flawlessly with the EZRUN MAX8 G2S electronic speed controller, which automatically recognises the matching motor through intelligent firmware integration. This pairing unlocks advanced features including optimised overheat protection that actively monitors motor temperature and prevents damage from excessive heat build-up.
• IP67 Waterproof Rating — The patented waterproof design protects both the output shaft position and the wire outlet housing, whilst a new generation induction line interface ensures outstanding water and dust resistance. This means your motor will confidently handle wet conditions, muddy tracks, rain showers and harsh outdoor environments without concern, making it perfect for UK racing in all seasons.
• Premium Aluminium Alloy Construction — The motor features a high-hardness aluminium alloy CNC-machined shell that provides excellent heat dissipation while maintaining structural rigidity. The precision engineering ensures tight tolerances and long-term reliability, even under the stresses of competitive racing or aggressive bashing.
• High-Quality Ball Bearings — First-line brand ball bearings in both front (D16×D5×T5) and rear (D11×D5×T5) positions ensure smooth rotation with minimal friction and excellent durability. These premium bearings reduce energy loss and allow the motor to spin freely, maximising efficiency and extending bearing life even with regular use.
• Ultra-Thin Silicon Steel Sheets — The stator uses ultra-thin, first-line brand silicon steel laminations that reduce electrical losses and improve magnetic efficiency. This engineering choice allows the motor to convert more of your battery's energy into useful mechanical power rather than wasting it as heat.
• High-Temperature Resistant Copper Wire — The windings are constructed from high-temperature oxygen-free copper that maintains its electrical properties even during sustained high-power runs. This ensures consistent performance and prevents performance degradation from heat exposure.
• Durable Alloy Output Shaft — The high-toughness alloy output shaft resists bending and stripping under the stresses of acceleration, braking and cornering. The 5.0mm diameter shaft accepts standard RC car pinions and provides a reliable mechanical interface between the motor and your vehicle's transmission.
• 4-Pole Configuration — The four-pole motor design delivers a good balance between power, efficiency and smooth operation, making it ideal for 1/8th scale vehicles where neither extreme weight nor excessive heat generation is desirable.
• 6.5mm Bullet Connectors — The standard 6.5mm bullet connectors ensure secure, low-resistance electrical connections to your ESC. These industry-standard connectors are universally compatible with most quality ESCs and offer easy soldering for quick replacements if needed.

Technical Performance

The EZRUN 4278SD 2250KV represents a significant leap forward in 1/8th scale motor technology, delivering performance that brushless RC motors simply couldn't achieve just a few years ago. With a 42mm outer diameter and 78mm length, this motor provides a powerful yet compact package that fits standard 1/8th scale RC vehicles without requiring chassis modifications. The 465-gram weight is carefully engineered to provide adequate cooling surface area whilst remaining light enough to maintain excellent handling characteristics in your RC buggy or monster truck.

The 2250KV rating determines how many revolutions per minute (RPM) the motor produces per volt applied to the motor windings. With a 3-6S LiPo battery compatibility range, this motor adapts to different power setups: running on 3S LiPo provides excellent torque and smooth acceleration for technical courses, whilst 6S LiPo maximises top speed for open layouts or speed trials. The no-load current of just 5.3 amps demonstrates exceptional electrical efficiency, meaning less current is wasted spinning the motor without a load, resulting in longer runtimes and cooler operating temperatures during actual use.

The high-hardness aluminium alloy CNC shell provides superior thermal conductivity compared to standard motor cans, allowing heat to dissipate more effectively during high-performance runs. Combined with the ultra-thin silicon steel sheets and oxygen-free copper windings, this motor minimises energy losses and converts more of your battery's energy into usable power at the wheels. The precision ball bearings at both front and rear positions ensure minimal friction and smooth rotation throughout the motor's RPM range, whilst the high-toughness alloy output shaft provides the durability needed for competitive racing or aggressive bashing on UK tracks and terrain.

What's in the Box

• Hobbywing EZRUN 4278SD 2250KV brushless motor
• Motor documentation and specifications

What You Need to Complete

• Hobbywing EZRUN MAX8 G2S electronic speed controller (ESC) or compatible 1/8th scale ESC
• 3-6S LiPo battery pack (3S, 4S, 5S or 6S compatible)
• LiPo battery charger (if not already owned)
• RC vehicle with 1/8th scale chassis compatible with this motor size
• Motor pinion and spur gear set appropriate for your desired gearing ratio
• Motor heatsink (optional but recommended for extended high-performance runs)

Frequently Asked Questions

• Is the Hobbywing EZRUN 4278SD 2250KV sensored motor good for beginners? — Yes, this motor is excellent for beginners because the sensored design provides smooth, linear power delivery without cogging, making it much easier to control and learn smooth driving techniques. The brushless design requires no maintenance unlike brushed motors, and the compatibility with the EZRUN MAX8 G2S ESC means you get intelligent overheat protection that prevents accidental damage from overheating.
• What battery does this Hobbywing motor need? — The EZRUN 4278SD is compatible with 3S, 4S, 5S and 6S LiPo battery packs. For beginners, a 4S LiPo (14.8V) provides an excellent balance of power and handling characteristics. More experienced racers often use 5S or 6S LiPo for maximum top speed, whilst technical courses may benefit from the smoother, more torquey characteristics of a 3S configuration.
• What is the difference between sensored and sensorless brushless RC motors? — Sensored motors like this EZRUN 4278SD use internal Hall effect sensors to provide real-time feedback about rotor position, allowing the ESC to commutate the motor perfectly smoothly from a standstill. Sensorless motors must estimate rotor position, which can result in cogging and hesitation at very low speeds. For 1/8th scale racing applications, sensored motors provide superior throttle linearity and more predictable handling.
• Why is the EZRUN MAX8 G2S ESC the perfect match for this motor? — The EZRUN MAX8 G2S ESC features automatic motor recognition firmware that identifies when you've connected this specific EZRUN 4278SD motor. Once recognised, the ESC adjusts its internal parameters for optimal performance with this exact motor, including custom acceleration curves, temperature thresholds and overheat protection algorithms that work seamlessly with this motor's thermal characteristics.
• Is this motor waterproof for wet UK weather and muddy tracks? — Yes, the EZRUN 4278SD features an IP67 waterproof rating through Hobbywing's patented waterproof design for both the output shaft and wire outlet housing. The new induction line interface provides outstanding water and dust resistance, meaning this motor will reliably handle rain, mud splashes and wet conditions without electrical failure.
• What is the weight and size of this motor? — The EZRUN 4278SD weighs 465 grams with a 42mm outer diameter and 78mm length. These dimensions are standard for 1/8th scale motors and will fit into any modern 1/8th scale buggy or monster truck chassis designed for standard-sized motors. The 5.0mm diameter shaft accepts standard RC pinions without modification.

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 HOBBYWING EZRUN 4278SD 2250KV BLACK G2R 1/8TH SENSORED MOTOR HW30402141 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.