New Train

[tender1]

Hello can some one tell me how to break in a new Ho engine.
Thank you, Tender1

[ABC]

As ABC suggested; running a locomotive in both directions at various speeds on a figure 8 is probably the best way to go. If you don't have the space for a figure 8 (or don't want to spring for all that track and crossing), the wheel rollers work very well. They can be had at Micro Mark.

[Joe Satnik]

Or, spend some of your break-in time going one direction around the oval, then pick it up, turn it around, and then go the other....

Edit: added "pick it up...."