Traction Issues with Old Style Plarail James

Hi guys, back again needing help with one of my plarail engines. I recently acquired the older style of the Thomas Plarail James engine with the battery in the tender compartment, and he works fine with one exception. He seems to have traction issues on the curves and can barely pull a single car without struggling immensely. Now, I will say that I am running him on the newer style of Trackmaster track (grey with open-air sleepers) but there are two caveats to this: one, I have tried him on the TOMY blue track and have been having the same issue, and two, other tender-powered, engine-driven Thomas characters including old-style Edward and Henry have no problem navigating the curves at all on TOMY or Trackmaster track. Any advice you guys can give me on how to improve James's performance would be awesome!