How do i find one set up for 2-4 psi?
The output pressure of a mechanical fuel pump is determined by the strength of the spring that is incorporated into the linkage. The camshaft lobe moves the diaphragm and creates the suction that the pump develops- - - -the spring pushes the diaphragm down as the cam lobe releases the lift, and the stronger the spring, the higher the deadhead pressure against the needle valve in the carburetor will be. A rebuilder such as "Then and Now" knows this, and they will install the correct spring for the application. A good pressure regulator between the pump and the carb will bypass part of the fuel flow back to the inlet side of the pump and control pressure that way.
Jerry
