I have a 2026 engine that does everything it should except the armature does not spin. I did check the armature for short between the shaft and the windings; OK there, and the armatures 3 copper plates check OK. The steel brush/spring cylinders can get hot when in the run foreword or backwards state. The e-unit is working fine, as is the light and the smoke unit. What is the best way to test the motor's field winding to see if it is working/not working? Also, is the motors field winding electrically isolated from the frame? I see that the wire schematic shows the steel plate connected to ground at one point.