Well , I'm just fishing, then.

It makes little sense that the engine will run most of the tank out and be fine, then go sour. That points to a tank problem or an overheating problem in my mind.

Do you know anyone who has some Cool Power 30% heli fuel? If so, give it a try and let me know the result. Don't forget to reset the needles when you make the change. If it works, it won't be the first time I was right!

Like I said, I'm fishing at this point.