I recently purchased a 151 which is in good condition. I wired it to an insulated rail and it works fine the first couple of times the train passes. On subsequent passes, the arm goes down and holds position for a while but then starts to jump. When I touch the mechanism, it feels very hot. Could the heat be causing this condition??
If its on too long or very often at high voltage it will get hot. Heat is never good for a coil so use the lowest voltage possible.
What you describe is a common problem caused by dirty wheels and/or the track section.
I have all accessories connected to the constant voltage of a KW … would track power work better?? Any other suggestions?