I have the PS2 version of this engine and it's set up as a diesel. It may be a steam engine, but the running gear is more akin to a diesel. If you can find an upgrade kit it needs to be the diesel kit. I haven't had need to open the tender up, but all that's in it is the backup lights, rear markers, the proto coupler. On mine MTH used their wireless tether to carry those wires from the PS2 board to the tender, so your going to need some sort of tether.