The engine on about 1/3 of the time will not move when the throttle is advanced, but the sound activates like the engine is moving. If the engine is turned on and off several times it will move. It runs just fine when after it starts to move, but when trying to reverse, it will not move. Does it need to be returned for service or is there something that can be re-programed? Any ideas?
I expect that the bevel drive gears have moved slightly out of place, or may be slipping on the drive rod. I had trouble with one of my Shays that I finally fixed by replacing its beveled truck gears with steel gears from NorthWest Short Line. Arthur
Return it for warranty repair.