I have one from the first run, and it ran erratically. Torqued my lugnuts when there was a cost associated with getting it repaired, a cost to ship and then have to wait for the turn-around. I decided to dive in and tear it down, it ended up being a wire lead at the front of the chassis (headlight or number boards) crushed between the boiler and frame where the front attachment screw resides. Once liquid taped, rerouted and reassembled it has worked pretty well.
The S.