Hi guys, I recently purchased a BX22 with a belly mower. Attempted to use it the other day and it cuts too low. I have the mower manual and it had a chart to set up the mower. Attempted to adjust with the knob just below the seat. It was set for 1.5 and tried to adjust to 2.5 to 3 inch. Raised mower then turned knob; would turn a little each way but could not turn from low setting to high setting. Should this be adjusted with mower deck up or down or does it matter. What am I actually adjusting. Any help would be appreciated. Thanks in advance