Hi Guys,
I know first hand, that the Ultra Stick 60 can handle a large motor.
I put in a Thunder Tiger 120 side exhaust 3.2 HP engine in mine. Just needed to butcher the motor mount and it fit. I installed a 4 cell 1100 mah battery as close to the tail as possible, Plus 6 O.Z. of lead under the very end of the Fuse. It ballanced perfectly with 4" light wheels and quad flaps.
Believe me it was still a floater.
***But when you applied full throttle, it would do an unbelievable job of going verticle like a bullet using the weakest 15X8 prop.***