Martin Taylor

Hi Guys,  I have a problem witha lack of power for my BAE Hawk. The Hawk comes with a 64mm 6 blade fan unit, the flying weight is around 620g and I am using a 11.1v lipo and 40A ESC. I thought I could use the motor from my now deceased Phase 3 Fantom (not crashed by me!!). I fly off tarmac and thought I should be able to ROG easily but when the throttle is opened up the Hawk just trundles along the runway but doesn't build up enough speed to take off.  My questions are: Could the Kv rating of the motor not be enough? Is it simply a case of getting a motor with a higher Kv rating to turn the fan quicker?  Any help or thoughts would be appreciated.