As I was pulling my motor by myself the other night using straps and a jack I realized that there is a very simple way to install/remove these motors (750 at least), if you have some help. A friend and myself were contemplating how the factory installed the motor in these bikes so fast. They probably installed the frame on the motor!
However, as I was looking for points to attach my straps to, it hit me. If you were to get some steel round stock to fit in both lower mounting points (front and rear) and slide it through to the other side, the motor can be lifted much like an old school gurney with the handles on each end. Two people could easily orient the motor in the proper angle and slide the motor right into the frame. I used this method with tie-down straps and was able to pull the motor by myself with absolutely no motor to frame contact. Once oriented in the frame, a jack can easily support the weight of the motor while the the steel rod is removed from the mounting points. Then a simple lowering of the jack will drop the motor right into place. Of course, to remove the motor using this method you would simply jack the motor up until the motor mounts were accessible and slide the round stock in place.
Just thought I would throw this out there!