Considering the look of the piston, and the fact that the engine MELTED the heat shield (The yellow sleeve over the fuel line), I would say that you were running WAY too lean. IF the engine still runs, you should richen it up quite a bit. Also, I would recommend investing in a temp gun. A cheap one will run you about $25, a LOT cheaper than a new $100+ engine, which will probably not last too long running as lean as this one was.

There are a few threads on here with great tuning tips. Take the time to read through them, and take it slow with tuning your engine next time around. Watch for a nice steady trail of smoke coming from the exhaust, and keep the temps in the 240-260 range on the Traxxas engines. (Some will still run great a little hotter, but until you are more comfortable with tuning, that is a good heat range to stay in).

Hopefully I don't come off as an @$$ in this thread, but you did say "Dont be afraid to lay it on me,"

Good luck.

Rocco, that heat shield won't melt like that, even running in the 260-270 range. It looks like he was running a LOT hotter than that.