Hi. I have a tub faucet handle that only turns halfway: 3 o'clock is the off position and only turns counter clockwise 90 degrees to the 12 o'clock position, although hot is at 9 o'clock. I've taken the handle off to try and adjust the 'stop' position but am unclear on how to proceed. There is a small white plastic 'stop' on the left of the stem that is controlling the movement of the handle.
See pictures attached.
Thanks!

