I have the lexani sr-71 I bought just airframe and wanted to use better motors and gear then what I been reading in the forums about this RTF versions. I bought a pair of electricfly 4850 motors put them in the 64mm fans, balance the unit and with 40amp esc and a 4s 5000mah battery, wired the esc in parallel the first time I test ran the unit and im not talking wide open maybe 1/4 stick the motors smoked and melted the ESC