Hi Gang,
I recal reading a post not long ago but never got to give my input.
Some one wanted info on testing and measuring the thrust of the engine.
Heres how I did it and this came from a Bell Helicopter engineer.
Plece the craft on level wood platform.
Try to get the best scale you can.
(Avoid fishing scales)

.Use a thin non stretchable cord.
Run the engine up.
Also make sure there is nothing at the rear for the prop blast to blow against.
Tie the craft in an open area.
Run up full throttle and then slide back down slow.
Go back slow and slide down fast.
Repeat these steps several times and your readings at full bore should always come out the same