Emax USA

EMAX ECOII 4320 Brushless Motor

$40.99 USD Sold out
KV
Notes
ECO II SERIES / LARGE MULTIROTOR POWER
Brushless Motor Platform

EMAX ECO II 4320

The EMAX ECO II 4320 is a large-format brushless outrunner for 13- to 15-inch FPV, long-range and heavy-lift multirotors. Four windings—350KV, 380KV, 420KV and 500KV—cover 6S through 12S systems around a 12N14P architecture, M6 propeller shaft and four-hole 30 × 30mm airframe mount.

Four KV options. One 4320 platform.350KV / 380KV: 8S–12S420KV: 8S500KV: 6SPublished propeller range: 13–15 inches
Motor weight298gIncluding 400mm leads
Motor sizeØ50.6mm68.7mm overall length
Mount30 × 30mmExactly four M4 holes
Framework12N14PLarge outrunner architecture
EMAX ECO II 4320 brushless motor for 13- to 15-inch multirotors

Large-prop power across four windings. Official EMAX bench sheets recorded up to 9.281kg of thrust, while the 350KV through 500KV range supports 6S–12S aircraft configurations.

01 / KV Selection

Match winding, voltage and propeller load.

Electrical limits and bench highlights come from the official ECO II 4320 specification and load-test sheets.

350KV
8S–12S / 13–15-inch props
Idle current1.5A @ 10V
Resistance47mΩ
Published peak82.1A / 3847W
Bench: 9.281kg at 47.04V, HQ1308 three-blade.
380KV
8S–12S / 13–15-inch props
Idle current1.7A @ 10V
Resistance44mΩ
Published peak69.3A / 3274W
Bench: 8.507kg at 47.24V, GF1308 three-blade.
420KV
8S / 13–15-inch props
Idle current1.9A @ 10V
Resistance39mΩ
Published peak82.5A / 2556W
Bench: 8.243kg at 30.96V, HQ1507 three-blade.
500KV
6S / 15-inch props
Idle current2.8A @ 10V
Resistance30mΩ
Published peak74.7A / 1797W
Bench: 6.490kg at 24.05V, HQ1507 three-blade.
EMAX ECO II 4320 KV guide for 350KV, 380KV, 420KV and 500KV windings
02 / Performance Envelope

Maximum recorded thrust by winding.

350KV
9.281kg
380KV
8.507kg
420KV
8.243kg
500KV
6.490kg

Configuration-dependent maximum-throttle bench results from official EMAX load-test sheets.

03 / Construction

Large-outrunner hardware with precision support.

01 / SHAFT

Steel M6 Shaft

A CW-threaded M6 propeller interface and 6mm bearing section support the rotating assembly.

02 / ROTOR

Anodized Rotor Bell

The rigid outer bell surrounds a full-height 14-pole permanent-magnet ring.

03 / STATOR

12-Slot Wound Stator

Dense multi-strand copper windings form the fixed 12-slot stator.

04 / BEARING

Precision Bearing

Concentric bearing support promotes smooth rotation under sustained load.

05 / MOUNT

Four-Hole Mount

The 30 × 30mm base has exactly four M4 airframe mounting holes.

06 / LEADS

400mm 16 AWG Leads

Long silicone motor leads provide routing flexibility in large aircraft.

Exploded ECO II 4320 motor showing steel shaft, full-height magnet ring, wound stator, precision bearing and four-hole mount
04 / Mechanical Data

4320 geometry and installation details.

Motor model EMAX ECO II 4320
Framework 12N14P
Motor diameter Ø50.6mm
Overall length 68.7mm
Weight 298g with wire
Bearing shaft Ø6mm
Propeller shaft M6 CW thread
Mounting pattern 30 × 30mm, four M4 holes
Motor leads 400mm 16 AWG silicone wire
Propeller range 13–15 inches, KV-dependent
One platform, four power profiles.

The shared 4320 mechanical package lets builders choose voltage and winding without changing the four-hole airframe interface.

The official drawing specifies 50.6mm diameter, 68.7mm overall length and a 30 × 30mm four-M4 mounting pattern.

Installation note: Confirm frame clearance, screw engagement, propeller retention, ESC headroom and cooling before operation.

EMAX ECO II 4320 12N14P motor platform for 13- to 15-inch FPV aircraft
05 / Electrical Specifications

KV-specific published limits.

KV Cells Propeller Idle current Resistance Peak current Max power
350KV 8S–12S 13–15" 1.5A @ 10V 47mΩ 82.1A 3847W
380KV 8S–12S 13–15" 1.7A @ 10V 44mΩ 69.3A 3274W
420KV 8S 13–15" 1.9A @ 10V 39mΩ 82.5A 2556W
500KV 6S 15" 2.8A @ 10V 30mΩ 74.7A 1797W
06 / Bench Data

Maximum-throttle load-test highlights.

350KV load-test highlights13–15-inch propellers
Voltage Propeller Current Thrust Power Efficiency RPM
47.04V HQ1308, 3-blade 75.73A 9,281g 3562.34W 2.61g/W 12,303
46.86V HQ1309, 3-blade 82.10A 8,845g 3847.21W 2.30g/W 12,046
47.06V GF1310, 3-blade 72.80A 8,410g 3425.97W 2.45g/W 12,375
32.68V HQ1507, 3-blade 56.60A 7,104g 1849.69W 3.84g/W 8,582
32.50V HQ1510, 3-blade 62.80A 7,092g 2041.00W 3.47g/W 8,326
380KV load-test highlights13–15-inch propellers
Voltage Propeller Current Thrust Power Efficiency RPM
32.49V GF1309, 3-blade 55.14A 6,214g 1791.50W 3.47g/W 9,354
32.36V HQ1507, 3-blade 67.36A 7,627g 2179.77W 3.50g/W 8,921
47.24V GF1308, 3-blade 69.30A 8,507g 3273.73W 2.60g/W 13,623
420KV load-test highlights8S / 13–15-inch propellers
Voltage Propeller Current Thrust Power Efficiency RPM
31.23V HQ1309, 3-blade 62.46A 6,104g 1950.63W 3.13g/W 9,924
30.96V HQ1507, 3-blade 82.57A 8,243g 2556.37W 3.22g/W 9,267
32.46V 1507, 2-blade 60.82A 7,032g 1974.22W 3.56g/W 10,395
500KV load-test highlights6S / 15-inch propellers
Voltage Propeller Current Thrust Power Efficiency RPM
24.37V 1507, 2-blade 52.90A 5,247g 1289.17W 4.07g/W 9,162
24.16V 1510, 2-blade 69.38A 5,510g 1676.22W 3.29g/W 8,558
24.05V HQ1507, 3-blade 74.70A 6,490g 1796.54W 3.61g/W 8,345
24.11V GF1507, 3-blade 71.54A 5,971g 1724.83W 3.46g/W 8,437
EMAX ECO II 4320 package with four M4 by 12 millimeter screws and one steel M6 nylock nut
07 / In The Box

Motor and mounting hardware included.

1×EMAX ECO II 4320 brushless motor
4×M4 × 12mm mounting screws
1×Steel M6 nylock nut

Bench-test note: Performance figures are measured test data, not guaranteed aircraft-level performance. Current draw, thrust, efficiency, RPM and temperature vary with propeller, battery voltage and sag, ESC behavior, airflow, ambient conditions and test equipment. Confirm the selected motor, propeller, ESC, battery and cooling for the complete aircraft.
Product information

All parts are shipped fast from SYRACUSE, NEW YORK & some DROP SHIP ORDERS from San Diego, California. If there's an issue with something, please let us know and we will do our best make it right! SaltCtyRacingFPV, LLC dba "weBLEEDfpv.com" offers a (30) day return policy on all new unopened equipment, starting from the date the product(s) was delivered to the customer. Anything beyond (30) days of delivery will not be eligible for return. If the product(s) received have been opened, used or damaged, no return options will be offered. If the item is in brand new condition but requires to be repackaged, a (15%) restocking fee will be applied. The shipping cost for any unwanted product will not be refunded by SaltCtyRacingFPV "weBLEEDfpv.com" (It is recommended to choose a return shipping method with tracking).

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⚠️ FPV DIGITAL SYSTEM NOTICE

HDZero, Walksnail, VTX systems, and ultra-micro FPV electronics generate heat quickly while powered and require proper handling during setup and troubleshooting.

Bench setup without airflow/cooling can result in excessive heat buildup.

Once powered, configured, firmware updated, soldered, flown, or modified, products are considered used.

Manufacturer warranty may apply for BNF drones and electronic systems.

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