Well ended up going with os 50 hyper. Added another 2 cell 2700 lipo. I am getting about 7 to 8 min flight did 3 flights and packs was at 4v so not to bad. Come access a major problem the next day went out to start it and this was twice now that this happened the nut that holds fan and clutch on came lose! After twice I started to investigate the problem the previous owner when putting it together put the starter shaft that goes through clutch bell in wrong. He put the shaft flush with the bottom of the bell instead of putting the hold pin in the grove on shaft it was at bottom. That I think was making the nut on motor back off, don't know how it even started because it was hardly going in the one way bearing on clutch. Other than that helie flew nice motor was a lot quiter than I thought it would be running real rich so hopefully this starter issue will be fixed and can get some more flights on it to dial in the motor.