Fresh batteries.. meaning what? Alkaline or NiCd - NiMH rechargeable?

Your original post did not discuss transmitter batteries so I had to take the devil's advocate here and suggest that the TX batteries could.. COULD be at fault, not necessrily at fault... but this must be ruled out.

What I mean here is that you could have had two separate problems. The TX battery pack AND the ESC - motor issue.

I had a plane that came with a two cell LiPo battery, so I flew it with that. It flew just great. A short time later, I thought, well, if a 480mah 2 cell LiPo would be ok, then a 3 cell LiPo of the same capacity should be better, right? Well, it did not take long to fry that motor, I'll tell you that!! Smoked it big time. And I am not sure about the ESC at this point. That remains to be seen because when I fried it, it was toward the end of last season and I shelved it for the time being. I will ressurect it soon and play with it. This is one reason I like my glow planes.. there are more, but this is one main one. There are no multiple potential issues with these things. When they run right, they run right. I don't have to change batteries, worry about the ESC or if I overcurrent the motor, none of that stuff. Just the right fuel, a well tuned engine, charged batteries, and I fly all day.

Meanwhile, good luck finding that problem. Let us know what caused it.

CGr.