Hello. Just found this forum. I purchased a Maxi starter set 54402 when my kids were little. Used around the Christmas tree primarily. Trying to do the same with grandchildren.
The train will only go in reverse and only at full speed.

Is this a common problem? Can anyone help me find a solution?

Thanks!

The 1996 catalog says for 54402 "Tank locomotive with built-in electronic circuit plate for operation with AC power or Marklin Delta. Electronic circuit plate included for operating the locomotive with DC power." The image of the trafo looks like an analog 6647 for 230V; the text says the US version of the set comes with a 6627 for 110V which has a blue plastic case.

So it sounds like you should be able to run it without a Delta controller; I think you can reverse the direction by turning it around on the track as suggested above, or by switching the power leads on the trafo. If it's only going at full speed, you may have power coming from the L circuit which is for lighting and accessories. Be sure to use the B and O connections on the trafo to get variable speeds.

I'm not familiar with the Maxi line so I don't know if the reversing function on the 6627 will do anything. It's the far counterclockwise momentary position past "0" which gives a momentary ~27V pulse to HO-scale reversing units.

I hope this helps.
Brian