ECOII Series / 43XX / ECO II

ECO II 4320 Brushless Motor

A high-power 4320-class aircraft motor with four KV options for 13 to 15 inch propeller systems and demanding aerial platforms.

350KV380KV420KV500KV

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KEY FEATURES

Designed for FPV performance tuning

Four KV choices cover 6S, 8S, and 12S test configurations with 13 to 15 inch propellers.
Precision bearings, a steel shaft, multi-strand winding, and an anodized motor structure support reliable high-load operation.
A 30 x 30 mm four-hole M4 mounting pattern, 400 mm 16 AWG silicone leads, and an M6 propeller shaft simplify aircraft integration.
Verified load-test data is provided for every KV option, including voltage, current, thrust, power, efficiency, RPM, and throttle.

SPECIFICATIONS

Product snapshot

Stator Size: 4320
Series: ECO II
KV Options: 350KV, 380KV, 420KV, 500KV
Motor Dimensions: 50.6 x 68.7 mm
Framework: 12N14P
Weight: 298 g including wires
Propeller: 13-15 inch
Bearing Shaft: 6 mm
Prop Adapter Shaft Thread: M6
Shaft Thread: CW
Mounting Pattern: 30 x 30 mm, 4 x M4
Lead: 400 mm 16 AWG silicone wire

VARIANT SPECIFICATIONS

KV configuration matrix

KV	Battery cells	Propeller	Idle current	Internal resistance	Peak current	Maximum power
350KV	8-12S	13-15 inch	1.5 A @ 10 V	47 mOhm	82.1 A @ 12S	3847 W @ 12S
380KV	8-12S	13-15 inch	1.7 A @ 10 V	44 mOhm	69.3 A @ 12S	3274 W @ 12S
420KV	8S	13-15 inch	1.9 A @ 10 V	39 mOhm	82.5 A @ 8S	2556 W @ 8S
500KV	6S	15 inch	2.8 A @ 10 V	30 mOhm	74.7 A @ 6S	1797 W @ 6S

OFFICIAL GRAPHICS

Engineering drawing and specifications

ECO II 4320 Brushless Motor engineering drawing 1

ECO II 4320 Brushless Motor technical specifications
SPECIFICATIONS
Framework	12N14P
Length	68.7 mm
Diameter	50.6 mm
Battery cells - 350KV / 380KV	8-12S
Battery cells - 420KV	8S
Battery cells - 500KV	6S
Recommended propeller	13-15 inch
Weight (with wire)	298 g
Prop adapter shaft thread	M6
Bearing shaft	6 mm
Shaft thread	CW
FEATURES
Precision bearing
Steel shaft
Anodized finish
30 x 30 mm, 4 x M4 mounting-hole pattern
Multi-strand winding
400 mm 16 AWG silicone wire
PACKAGE INCLUDES
4 x M4 x 12 screws
1 x steel M6 nyloc nut

LOAD TEST DATA

Verified performance data

The following measurements are from EMAX load-test records. Results may vary with battery, propeller, environment, and installation conditions.

350KV

HQ1308, 3-blade

ECO II 4320 Brushless Motor 350KV - HQ1308, 3-blade
VoltageV	CurrentA	Thrustg	PowerW	Efficiencyg/W	SpeedRPM	Throttle%
48.08	2.99	1003	143.76	6.98	4294	30%
48.03	6.36	1821	305.47	5.96	5651	40%
47.96	11.5	2807	551.54	5.09	6943	50%
47.86	18.35	3878	878.23	4.42	8113	60%
47.72	27.55	5131	1314.69	3.9	9271	70%
47.56	39.3	6394	1869.11	3.42	10351	80%
47.34	55.02	7885	2604.65	3.03	11342	90%
47.04	75.73	9281	3562.34	2.61	12303	Max

HQ1309, 3-blade

ECO II 4320 Brushless Motor 350KV - HQ1309, 3-blade
VoltageV	CurrentA	Thrustg	PowerW	Efficiencyg/W	SpeedRPM	Throttle%
48.08	3.29	1102	158.18	6.97	4249	30%
48.02	6.98	1930	335.18	5.76	5580	40%
47.93	12.5	2902	599.13	4.84	6838	50%
47.8	19.9	3922	951.22	4.12	7985	60%
47.64	29.9	5103	1424.44	3.58	9115	70%
47.45	42.7	6319	2026.12	3.12	10166	80%
47.21	59.3	7631	2799.55	2.73	11135	90%
46.86	82.1	8845	3847.21	2.3	12046	Max

GF1310, 3-blade

ECO II 4320 Brushless Motor 350KV - GF1310, 3-blade
VoltageV	CurrentA	Thrustg	PowerW	Efficiencyg/W	SpeedRPM	Throttle%
48.09	3.02	950	145.23	6.54	4279	30%
48.04	6.33	1687	304.09	5.55	5640	40%
47.96	11.3	2606	541.95	4.81	6932	50%
47.85	18.1	3577	866.09	4.13	8119	60%
47.71	27.1	4691	1292.94	3.63	9290	70%
47.54	38.6	5831	1835.04	3.18	10370	80%
47.34	53.4	7022	2527.96	2.78	11398	90%
47.06	72.8	8410	3425.97	2.45	12375	Max

HQ1507, 3-blade

ECO II 4320 Brushless Motor 350KV - HQ1507, 3-blade
VoltageV	CurrentA	Thrustg	PowerW	Efficiencyg/W	SpeedRPM	Throttle%
33.46	2.35	768	78.63	9.77	2959	30%
33.42	4.97	1366	166.1	8.22	3902	40%
33.36	8.93	2097	297.9	7.04	4795	50%
33.27	14.3	2905	475.76	6.11	5629	60%
33.16	21.6	3836	716.26	5.36	6439	70%
33.02	30.6	4811	1010.41	4.76	7174	80%
32.87	41.7	5845	1370.68	4.26	7893	90%
32.68	56.6	7104	1849.69	3.84	8582	Max

HQ1510, 3-blade

ECO II 4320 Brushless Motor 350KV - HQ1510, 3-blade
VoltageV	CurrentA	Thrustg	PowerW	Efficiencyg/W	SpeedRPM	Throttle%
33.45	2.64	829	88.31	9.39	2929	30%
33.4	5.65	1462	188.71	7.75	3848	40%
33.32	10.1	2198	336.53	6.53	4708	50%
33.22	16.2	3018	538.16	5.61	5505	60%
33.08	24.3	3962	803.84	4.93	6290	70%
32.93	34.2	4890	1126.21	4.34	6998	80%
32.75	46.6	5868	1526.15	3.84	7685	90%
32.5	62.8	7092	2041	3.47	8326	Max

380KV

GF1309, 3-blade

ECO II 4320 Brushless Motor 380KV - GF1309, 3-blade
VoltageV	CurrentA	Thrustg	PowerW	Efficiencyg/W	SpeedRPM	Throttle%
33.32	2.47	647	82.3	7.86	3185	30%
33.28	5.15	1184	171.39	6.91	4196	40%
33.21	9.18	1827	304.87	5.99	5165	50%
33.11	14.71	2561	487.05	5.26	6099	60%
33	21.71	3336	716.43	4.66	6968	70%
32.86	30.23	4153	993.36	4.18	7786	80%
32.7	41.46	5132	1355.74	3.79	8578	90%
32.49	55.14	6214	1791.5	3.47	9354	Max

HQ1507, 3-blade

ECO II 4320 Brushless Motor 380KV - HQ1507, 3-blade
VoltageV	CurrentA	Thrustg	PowerW	Efficiencyg/W	SpeedRPM	Throttle%
33.31	2.75	845	91.6	9.22	3144	30%
33.26	5.85	1508	194.57	7.75	4140	40%
33.19	10.57	2307	350.82	6.58	5071	50%
33.07	17.12	3210	566.16	5.67	5949	60%
32.94	25.73	4186	847.55	4.94	6772	70%
32.79	36.24	5205	1188.31	4.38	7510	80%
32.61	49.99	6384	1630.17	3.92	8237	90%
32.36	67.36	7627	2179.77	3.5	8921	Max

GF1308, 3-blade

ECO II 4320 Brushless Motor 380KV - GF1308, 3-blade
VoltageV	CurrentA	Thrustg	PowerW	Efficiencyg/W	SpeedRPM	Throttle%
48.19	2.81	911	135.41	6.73	4686	30%
48.15	5.7	1603	274.46	5.84	6169	40%
48.09	10.15	2445	488.11	5.01	7623	50%
47.99	16.59	3486	796.15	4.38	8969	60%
47.86	25.26	4630	1208.94	3.83	10264	70%
47.7	35.93	5826	1713.86	3.4	11443	80%
47.51	49.37	7042	2345.57	3	12612	90%
47.24	69.3	8507	3273.73	2.6	13623	Max

420KV

HQ1309, 3-blade

ECO II 4320 Brushless Motor 420KV - HQ1309, 3-blade
VoltageV	CurrentA	Thrustg	PowerW	Efficiencyg/W	SpeedRPM	Throttle%
32.11	2.74	709	87.98	8.06	3432	30%
32.07	5.71	1242	183.12	6.78	4532	40%
32.01	10.17	1871	325.54	5.75	5559	50%
31.91	16.33	2589	521.09	4.97	6560	60%
31.8	24.08	3348	765.74	4.37	7457	70%
31.64	33.86	4167	1071.33	3.89	8337	80%
31.47	46.29	5041	1456.75	3.46	9171	90%
31.23	62.46	6104	1950.63	3.13	9924	Max

HQ1507, 3-blade

ECO II 4320 Brushless Motor 420KV - HQ1507, 3-blade
VoltageV	CurrentA	Thrustg	PowerW	Efficiencyg/W	SpeedRPM	Throttle%
32.09	3.46	986	111.03	8.88	3365	30%
32.04	7.35	1721	235.49	7.31	4405	40%
31.95	13.23	2601	422.7	6.15	5396	50%
31.83	21.46	3595	683.07	5.26	6293	60%
31.66	31.74	4601	1004.89	4.58	7111	70%
31.47	45.16	5800	1421.19	4.08	7856	80%
31.25	61.69	6956	1927.81	3.61	8605	90%
30.96	82.57	8243	2556.37	3.22	9267	Max

1507, 2-blade

ECO II 4320 Brushless Motor 420KV - 1507, 2-blade
VoltageV	CurrentA	Thrustg	PowerW	Efficiencyg/W	SpeedRPM	Throttle%
33.32	2.5	719	83.3	8.63	3590	30%
33.28	5.18	1309	172.39	7.59	4747	40%
33.22	9.25	2013	307.29	6.55	5843	50%
33.12	15.07	2856	499.12	5.72	6893	60%
33.01	22.52	3753	743.39	5.05	7840	70%
32.87	32.26	4740	1060.39	4.47	8768	80%
32.69	45.04	5832	1472.36	3.96	9619	90%
32.46	60.82	7032	1974.22	3.56	10395	Max

500KV

1507, 2-blade

ECO II 4320 Brushless Motor 500KV - 1507, 2-blade
VoltageV	CurrentA	Thrustg	PowerW	Efficiencyg/W	SpeedRPM	Throttle%
25.12	2.5	513	62.8	8.17	3119	30%
25.08	4.94	944	123.9	7.62	4117	40%
25.02	8.64	1483	216.17	6.86	5082	50%
24.94	13.72	2100	342.18	6.14	5996	60%
24.84	20.61	2828	511.95	5.52	6868	70%
24.71	29.27	3593	723.26	4.97	7644	80%
24.55	39.85	4416	978.32	4.51	8425	90%
24.37	52.9	5247	1289.17	4.07	9162	Max

1510, 2-blade

ECO II 4320 Brushless Motor 500KV - 1510, 2-blade
VoltageV	CurrentA	Thrustg	PowerW	Efficiencyg/W	SpeedRPM	Throttle%
25.13	3.23	691	81.17	8.51	3067	30%
25.06	6.62	1191	165.9	7.18	4020	40%
24.98	11.68	1797	291.77	6.16	4924	50%
24.88	18.54	2483	461.28	5.38	5756	60%
24.75	27.63	3190	683.84	4.66	6547	70%
24.57	39.25	4010	964.37	4.16	7214	80%
24.38	52.97	4773	1291.41	3.7	7890	90%
24.16	69.38	5510	1676.22	3.29	8558	Max

HQ1507, 3-blade

ECO II 4320 Brushless Motor 500KV - HQ1507, 3-blade
VoltageV	CurrentA	Thrustg	PowerW	Efficiencyg/W	SpeedRPM	Throttle%
25.07	3.53	794	88.5	8.97	3025	30%
25.01	7.29	1378	182.32	7.56	3961	40%
24.93	12.8	2060	319.1	6.46	4824	50%
24.82	20.24	2826	502.36	5.63	5618	60%
24.68	30.03	3671	741.14	4.95	6383	70%
24.51	42.01	4555	1029.67	4.42	7064	80%
24.3	56.6	5507	1375.38	4	7714	90%
24.05	74.7	6490	1796.54	3.61	8345	Max

GF1507, 3-blade

ECO II 4320 Brushless Motor 500KV - GF1507, 3-blade
VoltageV	CurrentA	Thrustg	PowerW	Efficiencyg/W	SpeedRPM	Throttle%
25.07	3.59	772	90	8.58	3031	30%
25.01	7.4	1356	185.07	7.33	3955	40%
24.93	13.06	2040	325.59	6.27	4821	50%
24.82	20.6	2780	511.29	5.44	5618	60%
24.68	30.2	3542	745.34	4.75	6389	70%
24.52	41.63	4314	1020.77	4.23	7095	80%
24.33	55.63	5182	1353.48	3.83	7757	90%
24.11	71.54	5971	1724.83	3.46	8437	Max

APPLICATIONS

Recommended use

large FPVlarge multirotor platforms13-15 inch propeller systemsheavy-lift aerial propulsionengineering and custom aircraft projectsspecialty builds