Need some help with a Marz. EXR comp fork. This fork seems very lound, the rebound seems to snap back, almost sounds like metal hitting metal at the top of the fork. Are there any other adjustments other then the air one at the top of the right leg? Are the two bolts on the bottom of the legs used for any adjustment, also the left leg has a plastic plug with a + and -, what is that for? Been a while since I've worked on a MTB, primarily been on my road bike for the last five years. Big difference.