O.S - Brushless Motor OMA 5020-490 image

O.S - Brushless Motor OMA 5020-490

Manufacturer: O.S Engines Product Code: OSMG9540

9540 Brushless Motor OMA 5020-490

Available - Ships in 2-5 Business Days


For airplanes using a .40 - .50 size 2-stroke engine or 4-stroke .70 engine
Centrifugal fan design with angled ventilation holes draws air through the motor and across the windings and magnets for improved cooling


.40 Brushless Electric Motor with Backplate, four Phillips Head
Mounting Screws, 4mm Gold Plated Male Plugs attached to leads,
three 4mm Female Plugs with Shrink Wrap, Prop Adapter and
Instruction Sheet


90A brushless ESC


Rated Power: 1110W
Rated Voltage: 18.5 - 22.2V
Rated Current: 50 - 60A
Maximum Current (10 sec): 90A
No Load Current: 1.5A
Phase Resistance: 23.0 miliohms
Maximum Efficiency: 85%
kV: 490
Poles: 14
Shaft Diameter: 0.20" (5mm)
Shaft Length: 0.45" (11.5mm)
Weight: 12.3oz (350g)
Lead Wire Length: 4.3" (110mm)
Length of Motor Can to Backplate: 2.1" (52.5mm)
Diameter of Motor Can: 1.98" (50mm)
Length/rear of Motor Can to Prop Washer: 2.7" (69mm)
Prop Washer Diameter: 1.06" (27mm)
Thickness of Motor Mount: 0.16" (4mm)
Width of Motor Mount: 2.67" (68mm)
Height of Motor Mount: 2.67" (68mm)

Performance for this motor with different props and LiPo cells is as

follows (all data with 80A ESC)

Prop Size Max Electric Current LiPo Cells

14 x 8 45A 6S
14 x 10 55A 6S
15 x 8E 50A 6S
15 x 10E 60A 6S
15 x 10E 42A 6S
16 x 8 58A 6S
16 x 10E 51A 5S


Nomenclature is defined as follows:
0MA denotes 0.S. airplane motor
First two digits are the rotor diameter
Second two digits are the length of the magnets
Last digits indicate the kV of the motor