The LPR for ’09 is basically the same as it has been since the ’06 remains
In 2009 recessing one spring inside the LPR body shortens the LPR.
A floating piston (3) is suspended between two O-Rings, one on the Piston (4) and one inside LPR body (1). The floating piston’s long appendage both conducts air and holds a seal that locks the incoming air. The spring (2) between the piston and the LPR body pushes the Piston away from the LPR body to allow air to escape through the LPR body (1). When the pressure becomes great enough it overcome the pressure of the spring (4) and the seal is pushed against a seat in the piston body so the airflow stops. A setscrew (7) in the LPR cap pushes the second piston (5) That piston pushes a lighter spring (4), against the same piston (3) as the stiffer spring. Screwing down the setscrew (7) increases the pressure on the lighter spring, lowering the LPR pressure. The balance between the two springs plus the pressure of the gas inside the cap is what regulates (changes) the operating pressure.