4-inch and light 5-inch FPV motor
BetaFPV 2004
A light motor for 4-inch quads and light 5-inch toothpicks: 16.62 g, and up to 1,086 g of thrust per motor on Gemfan 5125 three-blade props on BetaFPV's 16 V bench (3000KV).
- 4-inch quads and light 5-inch toothpicks; 3-inch ducted whoops (3000KV)
- 4S (3000KV) or 6S (1700KV)
- 5025 or 5125 props fixed with M2 screws
The spin is an illustration: the model turns at 1/600 of the no-load speed, and it is a generic 2004 motor drawn from BetaFPV’s published sizes, not its exact design. No-load speed is KV × 14.8 V, a nominal pack for this version. BetaFPV’s bench tables for it step by thrust rather than throttle, so they are in the bench data below, not on this readout.
- Weight
- 16.62 g
- both KVs; BetaFPV's spec list rounds it to 16.6 g
Plain links: we earn nothing from them.
What you get
16.62 g
Both KVs weigh 16.62 g per motor in BetaFPV's comparison chart.
Source: BetaFPV comparison chart
1,086 g on 4S
On BetaFPV's 16 V bench the 3000KV pulled 1,086 g on Gemfan 5125 three-blade props at 31.61 A; the 1700KV pulled 1,036 g at 24 V and 16.38 A.
Source: BetaFPV 3000KV sheet, BetaFPV 1700KV sheet
Open, tyre-like bell
BetaFPV likens the bell to a tyre and says its large surface sheds heat, keeping the motor cooler.
Source: BetaFPV product page
Anti-drop shaft
A peg in the hole of the shaft keeps the motor from coming apart in a crash; BetaFPV notes that a little looseness after a hit is normal.
Source: BetaFPV product page
What to pair it with
Our reading of BetaFPV’s numbers, so your build matches what the motor was tested with.
- ESC
- BetaFPV pairs it with its F405 flight controller and 35A ESC, or its 35A AIO board. Its bench reaches 31.61 A (3000KV, 16 V) and 16.38 A (1700KV, 24 V). (BetaFPV product page, BetaFPV 3000KV sheet, BetaFPV 1700KV sheet)
- Props
- 5025 or 5125 props fixed with M2 screws: BetaFPV lists HQ 5025 and Gemfan 5125 three-blades and Gemfan 5020, and benches the Gemfan 5125. (BetaFPV product page, BetaFPV 3000KV sheet)
- Battery
- 4S for the 3000KV (BetaFPV suggests its 450 mAh and 850 mAh 4S packs), 6S for the 1700KV (its 550 mAh 6S pack). (BetaFPV product page)
- Frame
- Four M2 screws on a 12 mm circle; BetaFPV recommends 4- to 5-inch frames, its TWIG ET5 toothpick frame in particular, and names its X-Knight and TWIG Mutant quads. (BetaFPV product page, BetaFPV 3000KV sheet)
Where to buy
- BETAFPVthe maker's store; $13.99 single, $51.99 for four 3000KV or $73.99 for four 1700KV; all sold out and tagged discontinued when checked$13.99seen Oct 19, 2026Visit
Plain links, not affiliate links. Prices change; the store’s page has the current one.
Full specs
| Spec | Value | Source |
|---|---|---|
| KV | 3,000 rpm/V (also 1700KV) | BetaFPV product page |
| Stator | 20 × 4 mm (2004) (from the size in BetaFPV's name) | BetaFPV product page |
| Battery | 4S (3000KV) or 6S (1700KV) LiPo | BetaFPV product page |
| Weight | 16.62 g (both KVs; BetaFPV's spec list rounds it to 16.6 g) | BetaFPV comparison chart |
| Dimensions | φ24.6 × 17.2 mm (with shaft); body 13.4 mm tall (BetaFPV's outline drawings give 13.2 mm for the body and 3.5 mm for the shaft) | BetaFPV product page, BetaFPV dimension photo |
| Shaft | 1.5 mm, unthreaded, protrudes 3.8 mm (props are held by M2 screws) | BetaFPV product page, BetaFPV dimension photo |
| Mounting | 4 × M2 holes on a 12 mm circle | BetaFPV product page, BetaFPV 3000KV sheet |
| Bell | two M2 prop-mount holes 5 mm apart | BetaFPV 3000KV sheet |
| Leads | 24 AWG, 100 mm | BetaFPV product page |
| In the box | 1 or 4 motors, a pack of M2 screws | BetaFPV product page |
Bench data
Redrawn from BetaFPV’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.
1700KV on 6S, 24 V1 prop
| Prop | Step | Thrust (g) | Current (A) | RPM | Power (W) | Efficiency (g/W) |
|---|---|---|---|---|---|---|
| GF 5125 3B (Gemfan 5125, 3-blade) | 200 | 1.93 | 13341 | 46.29 | 4.32 | |
| 300 | 3.15 | 16318 | 75.61 | 3.97 | ||
| 400 | 4.61 | 18789 | 110.69 | 3.61 | ||
| 500 | 6.85 | 21635 | 164.34 | 3.04 | ||
| 600 | 8.79 | 23309 | 210.94 | 2.84 | ||
| 700 | 10.73 | 24983 | 257.53 | 2.72 | ||
| 800 | 12.39 | 26115 | 297.34 | 2.69 | ||
| 900 | 14.05 | 27268 | 337.32 | 2.67 | ||
| 1,000 | 15.76 | 28535 | 378.35 | 2.64 | ||
| 1,036 | 16.38 | 28991 | 392.7 | 2.63 |
Source: BetaFPV 1700KV sheet
3000KV on 4S, 16 V1 prop
| Prop | Step | Thrust (g) | Current (A) | RPM | Power (W) | Efficiency (g/W) |
|---|---|---|---|---|---|---|
| GF 5125 3B (Gemfan 5125, 3-blade) | 200 | 3.87 | 14034 | 61.87 | 3.23 | |
| 300 | 5.95 | 17333 | 95.2 | 3.15 | ||
| 400 | 8.04 | 19163 | 128.69 | 3.11 | ||
| 500 | 10.53 | 20978 | 169.14 | 2.96 | ||
| 600 | 13.05 | 22573 | 209.55 | 2.86 | ||
| 700 | 16.26 | 24145 | 260.1 | 2.69 | ||
| 1,000 | 28.64 | 28957 | 458.31 | 2.18 | ||
| 1,086 | 31.61 | 29857 | 507 | 2.14 |
Source: BetaFPV 3000KV sheet
Inside the motor
A brushless outrunner: the coils stand still in the middle and the magnets spin around them. From the top down:
- Bell. Silver-grey, with a turbine-like top of ten curved spokes and blue inserts between them; two M2 prop holes 5 mm apart. (BetaFPV product page)
- Shaft. 1.5 mm and unthreaded, standing 3.8 mm above the bell, with a peg in its hole that BetaFPV calls an anti-drop design. (BetaFPV product page)
- Base. Four M2 holes on a 12 mm circle. (BetaFPV product page)
- Leads. Three 24 AWG wires, 100 mm long. (BetaFPV product page)
How fast it spins
KV is the motor’s no-load speed per volt. With nothing on the shaft, the 3000KV 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.
| Battery | Volts | No-load rpm (KV × V) | Electrical frequency | ESC steps per second |
|---|---|---|---|---|
| 4S nominal | 14.8 | 44,400 | 5,180 Hz | 31,080 |
| 4S full | 16.8 | 50,400 | 5,880 Hz | 35,280 |
| 6S nominal | 22.2 | 66,600 | 7,770 Hz | 46,620 |
| 6S full | 25.2 | 75,600 | 8,820 Hz | 52,920 |
A 14-pole rotor has 7 pole pairs, so every turn of the shaft is 7 electrical cycles, and a six-step ESC switches the phases 42 times per turn.
About the 3D model
A generic outrunner drawn from BetaFPV’s published sizes: the 20 × 4 mm stator, 24.6 mm bell, 13.4 mm height, 1.5 mm shaft and 12 mm mounting circle. Anything BetaFPV 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
- BETAFPV: 2004 Brushless Motors (product page; sold out and tagged discontinued when read). Retrieved Oct 19, 2026.
- BETAFPV: 2004 3000KV outline drawing and load performance table at 16 V (image on the product page). Rows step by thrust; BetaFPV leaves the throttle and coil temperature columns blank, so they are left out. The 800 g and 900 g rows are left out too (see the model notes).. Retrieved Oct 19, 2026.
- BETAFPV: 2004 1700KV outline drawing and load performance table at 24 V (image on the product page). Rows step by thrust; BetaFPV leaves the throttle and coil temperature columns blank, so they are left out.. Retrieved Oct 19, 2026.
- BETAFPV: Comparison of 2004 Motors chart (image on the product page). Retrieved Oct 19, 2026.
- BETAFPV: 2004 1700KV dimension photo (image on the product page). Retrieved Oct 19, 2026.
- BETAFPV: 2004 3000KV product photo (side view), used for finish. Retrieved Oct 19, 2026.
- BETAFPV: 2004 product photo (top view), used for the top colour and spoke count. Retrieved Oct 19, 2026.
