Agreed. After watching your video, you definitely have lubrication problems. You'll want to add a drop of oil to both ends of the armature shaft, and the rear driver where the drive rod attaches.
Given that your engine was the very lowest-priced steamer that Lionel ever made, it will be way more sensitive to track, wheel, and roller dirt than a more robust unit. That engine's rollers and ground points will be VERY touchy... especially in a public setting.