the plane is an me 262. the fans, the ESC's are new and the plane has not flown yet. I have ran the motors and just suspect that the thrust is not equal( no measurement is made) I am asking the question in case I CONFIRM SOME DIFFERENCES then I have some ideas where to look to make any corrections. the batteries are placed forward in the fuse and the ESC's are close to the leading edge of the wing( somewhat long wires between them). no obstruction in the ducts. A far as I know the the throttle position was learned but this can be checked again. Thanks for you response.