Hi pinsiders
I do not like to downvote - so I upvoted a post.
About unwinding one or two layers off a coil --- I read about, didn't believe - worked me out the solution "each bumper-coil gets its own rectifier" - with an minimum of altering wiring in the pin: The bumpers in my Shangri La changed from sluggish to lively. Greetings Rolf