I recently bought a used Lionel Amtrak GG-1 set with the locomotive and the 7 passenger cars. The engine itself is barely able to make it around the O36 fastrack turns. With the passenger cars, it barely moves on the straights. I tried pulling 6 of the cars with one of my steam engines, and the little thing was able to pull them fine! Anyone know what the problem could be and a solution? I appreciate any help!