I did exactly the same, thought I had been too rough with it but think I had put the coil in the wrong way round, upside down or on the wrong side of the bar, had very limited movement. Tried again and worked as before, full range again, might be worth giving it another go.That's how I mounted it. Handling could been a little rough...it seems when torching it until glowing, only gets to first VI mark...looks like I messed the calibration