Are you sure that is the correct coil stop for an EM game?
AC coil stops are slightly magnetic so that when the current alternates on and off 60 times a second, it doesn't completely let go, reducing the vibration.
I'm not sure if those stops are the right kind or not. Here's and old CARGPB trick. See if those coils stops are the same size as the stops on your credit unit. They should be, if they are, swap them. The credit unit coils didn't see near as much use and are usually in good shape. If the vibration reduces then you'll know it was the stops.
Great to see you're enjoying Pinside! Did you know Pinside is able to run thanks to donations from our visitors? Please donate to Pinside, support the site and get anext to your username to show for it! Donate to Pinside