I went out to the LHS track last night after work to play around. I ran for a tad over 50 minutes on each 4s 5Ah pack. Motor temp was a little high at 147*F at the end of the first pack, but it was 95*F outside so that's not that bad really.
I really love this truck! Perfect compromise between 1/8 scale durability and low power requirements of 1/12 scale. Even with 120k CD fluid, it still handles great. I thought my suspension would be a bit stiff for track use since I'm using Losi's stiffer gold springs, but it seemed to handle jump landings
much smoother than a Slash (also playing around there) did.
I went into the store to cool off after the first run and the guy with the Slash was in there buying a 3s pack. He had the top off the Slash and his motor was too hot for me to touch. He had been in there for ~5 minutes longer than I was and his motor was hotter sitting there than mine was coming right off the track.
Moller123456 !, I don't know why you are having so much trouble with your setup. Like E-Revonut said, it has to be something specific to your setup. If you lived a little closer to me, I'd offer to meet up with you to get it running right, but several thousand miles is just too long of a drive/swim.

Seriously though, once you get it running, I can almost guarantee you'll love it. Out of all the vehicle types/sizes I have, I like this one the most.