So my TZ has 15411 orange coils in the flippers. The resistance chart says these should have resistance of 4.2 ohm and 150 ohms. My right flipper measures 4.3 and 150, but my left one is not as snappy and measures 4.5/155.
What is the tolerance of a coil? A few tenths and a few ohms might not seems like much, but these measurements are halfway to the FL-11630 medium strength red coil which should be 4.7/161. Did I get a dud? Seems like coils generally fail from overheating or winding failure, and "drifting" out of tolerance doesn't make much physical sense.