iFlight Defender 25 1404

What it pulls

iFlight’s own bench test, one line per prop. Drag across the chart to move the throttle; the model above follows.

What you get for $13.99

• Made for the Defender 25

  iFlight designed it for ultralight sub-250 g builds on its Defender 25 frame with a whoop-style AIO board.

  Source: iFlight product page

• 8 g with wires

  On a 14 × 4 mm stator with a φ17.7 mm bell.

  Source: iFlight 4150KV test report

• Direction marks

  Sold with a CW or a CCW arrow lasered on the bell's top.

  Source: iFlight 4150KV test report

• Curved N52H magnets

  Arc-shaped N52H magnets, 12 poles on a 9-slot stator.

  Source: iFlight product page

• Single-strand windings

  One strand per tooth, 188 mΩ between phases.

  Source: iFlight product page

What to pair it with

Our reading of iFlight’s numbers, so your build matches what the motor was tested with.

ESC

Rated for at least 12 A, the peak iFlight measured at full throttle on the Defender 25's 2.5-inch tri-blade on 4S. (iFlight 4150KV test report)

Props

iFlight tested it with the Defender 25 2525 tri-blade: 140 g at half throttle and 350 g at full. (iFlight 4150KV test report)

Battery

4S. iFlight gives 16.8 V as the input. (iFlight product page)

Frame

Three M2 holes on a 9 mm circle, the Defender 25's pattern. Four M2×5 and two M2×7 screws come in the box. (iFlight product page, iFlight 4150KV test report)

Where to buy

• iFlightthe maker's store; one motor, CW or CCW mark
  $13.99seen Oct 19, 2026
  Visit
• GetFPVCW mark
  price on the store’s page
  Visit
• GetFPVCCW mark
  price on the store’s page
  Visit

Plain links, not affiliate links. Prices change; the store’s page has the current one.

Full specs

Bench data

Redrawn from iFlight’s test reports. Thrust is static pull on a bench, more than you get in flight. Power is volts × amps; efficiency is thrust divided by power.

Inside the motor

A brushless outrunner: the coils stand still in the middle and the magnets spin around them. From the top down:

• Bell. Segmented, in iFlight's words, φ17.7 mm, with four spokes across the top and a CW or CCW arrow lasered on it. (iFlight 4150KV test report)
• Shaft. Protrudes 1.8 mm above the bell; the drawing gives the tip as φ1.5 mm. (iFlight 4150KV test report)
• Magnets. Curved N52H magnets, 12 poles. (iFlight product page)
• Stator. 14 × 4 mm with 9 teeth, wound with single-strand copper; black 26 AWG leads, 60 mm long. (iFlight 4150KV test report)
• Bearings. NMB, 5 × 2 × 2.5 mm. (iFlight product page)
• Base. Three M2 holes on a 9 mm circle. (iFlight 4150KV test report)

How fast it spins

KV is the motor’s no-load speed per volt. With nothing on the shaft, the 4150KV version reaches about these speeds; a prop loads the motor and brings it down, typically to around 70–75% of these figures at full throttle.

A 12-pole rotor has 6 pole pairs, so every turn of the shaft is 6 electrical cycles, and a six-step ESC switches the phases 36 times per turn.

About the 3D model

A generic outrunner drawn from iFlight’s published sizes: the 14 × 4 mm stator, 17.7 mm bell, 12.5 mm height, 1.5 mm shaft, 9 mm mounting circle and 9 teeth and 12 magnets. Anything iFlight doesn’t publish is typical for a motor this size, and the bell’s spoked top, the base and the inside are a generic design, not this motor’s. The colours are read off the maker’s product photos. There are no logos or markings: it is our drawing, not the maker’s.

Sources

1. iFlight: Defender 25 Motor (product page, with its photo gallery). Retrieved Oct 19, 2026.
2. iFlight: Defender 25 1404 4150KV test report (spec table, dimension drawing, thrust data). Retrieved Oct 19, 2026.