I cleaned and calibrated the Filter King fuel regulator that is attached at the front of the engine. I also attached a fuel pressure gauge at the output of the regulator, to be sure I feed the proper fuel pressure to the carburetors. The manual recommends a minimum of 2 psi and a maximum of 4 psi. I chosen 3 psi.

        You can purchase a new one if you need from Pierce Manifolds in Gilroy, Ca. Here is a link to their website. This page from their website has the Filter King regulator and throttle linkages.

        This is the pressure regulator.