Hey Cecil. For this motor, the max thrust on a 3s lipo would be about 450 grams. Multiply that by 4 for 1800 grams total thrust. Unless you can build the quad for an all-up flying weight of 1/2 of that, these are too small for your quad. For great performance, you really need a 2:1 thrust to weight ratio. Estimate the weight of your quad's flying weight (select and estimate total of all parts) and look for a motor that can pull about 1000g thrust (or about 1/2 of your total flying weight). Hope this helps!
Update on motor, I contacted HK Customer support and sent them photo's of the defective motor, they refunded the cost of the motor in points(my choice) to my account, this was all done in less than 24 hours. Maybe HK is stepping up on the support, keep it up HK! Awesome.
I know this is not the review area but since my buddy made my purchase under his name, I can't do a review, so I will just mention it here for those that are interested. Received my motor unpacked it from the box and noticed there were 3mm bullets connector soldered onto the motor already, although only 2 remained attached. Also noticed a forth wire(another black) coming from the motor, never seen that before on a motor. I re-soldered new bullets onto the wires and connected the motor up, the motor looked like it tried to start when I throttled forward but would not spin. After inspecting the wires closer I noticed that the yellow wire was not even attached to the motor, it had a broken wire and with the poorly shrunk shrink wrap on the wires was difficult to see on my first inspection. The motor is useless, disappointed as usually Turnigy puts out good products, its a useless motor not, I took some pics so now I will see what HK customer support will do for me. 1 OUT OF 5 STARS FOR THIS MOTOR, VERY POOR ON QUALITY AND QUALITY CONTROL.
Great little Motor. I am using it for my 270gm J3 Cub. It is providing more than enough power. I am using both 2S and 3S Lipos. 3S I am using it with 8x4 props while the 2S I am using it with 9x7 props.