Config table shows 42 rpm/V, of course 4200 is correct.
Config table shows threads 4 x M2, there are 4 x M3.
Paper cover of motor was already lost at first test, with half power!
Although a nice motor.

this is a kick a** of engine !! low consumption and lots of power !

Cheap motor and it corresponds to the workmanship, not balanced or poorly balanced. The front motor plate for mounting EDF is 21.5 mm diameter, I had to grind to 20 mm
to fit the EDF 64 mm. But the reward for these shortcomings is a good performance.
My setting and measured values: model profile SU-27, weight 460 g, 64 mm EDF
12 blade rotor, nano tech11,1V 1800mAh 65C, 50A ESC - Power 480W, 43 A.
SU-27 flies at half throttle, it suits me. I am satisfied with it. For the price it is a good motor.
Time will tell how good it is.
Wish you a happy flight. St.Paul

Tuto bat som uz mal dva razy a vydy plna spokojenost,tajk som sa rozhodol objednat dalsiu a som spokojeny aj do buducna,takze urcite doporucujem kupit aj dalsie.sdbgh

These are garbage. The motor shaft is not secured to the outrunner. There's no grub screw. I can only assume they secured it with threadlock or a prayer. Save your money and get a Turnigy 2610, 2615, or 2815 instead. You'll be glad you did.

I tested this 4200kv motor.
Radjet 420 prop 3.75 x 3 (PRODUCT: 9310000021).
HK 30A ESC (PRODUCT: F-30A).

3s 2650mah 30C Lipo 50pcnt full (3.85v per cell):
It pulled max 370gr, ~30A.

3s 2650mah 30C Lipo 100pcnt full (4.2v per cell):
It pulled max 390gr, ~36A.

Total screamer - it hurt my ears when testing inside house. Now imagine two of these in a plane :0

Great little motor mine is putting out 400watts ish around 31 amps very reliable great price

Only an advertisement. I tried to use with a TGS Sport 4.5x4.5E and the motor burned. I will try next time with TGS Sport 4.1x4.1E.

Installs sur -10 warethog 55mm EDF. Vario x2 30a turbine du kit. Impeccable!

I put one of these in my 64 mm Grumman F9F, a serious upgrade from the stock 3000kv motor, on three cells it is off the grass in 20 ft and will run about 75 mph was around 55mph prior. I accidently put a 4 cell 1300 mah in and it flew faster estimated 90 mph but the stock esc couldn't handle it and burned up. The motor did not have any issues so a new ESC is in for next year. Great motor for upgrading from stock and it is tough. I'm buying more of this style for my planes as my winter upgrade project.