The issue: The motor runs but it has to be "kick-started", which cannot be accomplished with the trucks on. Runs at various speeds and voltages until stopped then has to be "kick-started" again.

Background: New N-Scale locomotive from a Stallion starter set. Worked well for about a half hour or so, after that only the headlight worked. There was evidence that it may have had a rough ride on the way to my house. The rear truck cover was loose but snapped back in place easily. I haven't checked the other cars in the set yet. Popped the shell and pulled the trucks, no visible connection issues between wheels and chassis.

Layout and power supply have been illuminated, other locomotives work fine. 

"Bench tested" the chassis... Jumpered the chassis halves to the power supply from the starter set via the rerailer section of track eliminating the trucks as a connection issue. Still no motor response only the headlight worked. Spun the worm gear with power at around 50% and VIOLA! The motor runs.

Once spinning the motor operates normally until stopped, even with a slight load applied to the flywheel or worm gear. Once stopped it won't restart until I spin the worm gear or flywheel again.

Questions: Is this a common problem? Is it repairable: connection between chassis, DC board and/or motor? Is it a motor issue: armature/field windings, replace the motor?

Any advice would be appreciated.

Richard