5-inch FPV racing motor
EMAX RSII 2207
EMAX’s Race Spec II motor in the 2207 size, in 1600KV, 2300KV and 2550KV, with a CW-threaded shaft.
- 5-inch racing
The spin is an illustration: the model turns at 1/600 of the no-load speed, and it is a generic 2207 motor drawn from EMAX’s published sizes, not its exact design. No-load speed is KV × 22.2 V, a nominal pack for this version. EMAX publishes no bench data for it.
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What you get
Three KVs
EMAX sold the RSII 2207 in 1600KV, 2300KV and 2550KV, each with a CW-threaded shaft.
Source: EMAX product page
Where to buy
- EMAXthe maker’s global store; one page for all three KVs (all listed as out of stock)$36.94seen Oct 19, 2026Visit
Plain links, not affiliate links. Prices change; the store’s page has the current one.
Full specs
| Spec | Value | Source |
|---|---|---|
| KV | 2,550 rpm/V (also 1600KV and 2300KV) | EMAX product page |
| Stator | 22 × 7 mm (2207) | EMAX product page |
| Shaft | CW thread (the RSII-2207CW) (EMAX’s page lists only the CW-thread version) | EMAX product page |
Inside the motor
A brushless outrunner: the coils stand still in the middle and the magnets spin around them. From the top down:
- Shaft. CW thread (the RSII-2207CW) (EMAX’s page lists only the CW-thread version). (EMAX product page)
- Stator. The coils are wound on a stack of thin steel laminations: 22 × 7 mm (2207). (EMAX product page)
How fast it spins
KV is the motor’s no-load speed per volt. With nothing on the shaft, the 2550KV 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 | 37,740 | 4,403 Hz | 26,418 |
| 4S full | 16.8 | 42,840 | 4,998 Hz | 29,988 |
| 6S nominal | 22.2 | 56,610 | 6,605 Hz | 39,627 |
| 6S full | 25.2 | 64,260 | 7,497 Hz | 44,982 |
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 EMAX’s published sizes: the 22 × 7 mm stator. Anything EMAX 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.