Richen your low end and try to get a skytach. Your engine is over heating and going lean. Try to find a local heli pilot to set your heli if you can if not make sure your pitch is set and than only adjust your thro curve to maintain the proper head speed which would be 1650-1750.

Thro curve should be 25 +/-, 50 , 75 , 100
Pitch curve - -2 , 4.5-5 , 9.5 max

Make sure you track your blades, from what you have said the blades are not in track.