I have read the procedures for starting in neutral, and locking in forward.  Have 2 powered F-3's and would like one to start in reverse to run A-B-A.  Is there a simple solution, similar to the start in neutral mod?

I received a new PA1 A-A on Tues.  Yesterday the PB1, the 4 car 72' set and the 2 car add on 72' arrived.
Running conventional, I assembled A-B-A and the six cars.  Engine pulled fine for 3 or 4 minutes, then slowed down to an eventual complete stop.  Forward portion of the shell on the powered felt significantly warmer that the rear motor area.
Oiled all wheels and lubed gears before starting the run.  Does this seem to be a warranty issue?  The A-A ran fine when I only had the two, but with this extra weight and interior lights, etc. drawing current, it seems to an overheating issue in one motor.
My first WBB purchase, so I would appreciate any guidance.