4305M

      The 4305M is competition fuel pressure regulator for fuel injection.This regulator must use a fuel return line. The fuel return line runs between the fuel bypass port of the 4305M regulator and the fuel tank. Fuel pressures cannot be adjusted if the fuel return line is absent.
      The 4305M regulator regulates fuel pressure between high pressure fuel pumps and fuel injection systems. The regulator is recommended for Mallory COMP PUMP® 60FI, 110FI, or any fuel injection pump designed to produce 30-100 PSI.
      The 4305M regulator is a return style fuel pressure regulator. The excess fuel and fuel pressure is sent back to the fuel tank through the fuel return line. The fuel return line runs between the fuel bypass port of the 4305M regulator and the top of the fuel tank. The fuel tank must have provisions for a fuel return line.This 4305M regulator is equipped with a vacuum/boost compensation port (brass barb fitting) that can be used to momentarily decrease fuel pressure (vacuum compensation) at idle and part throttle, or increase fuel pressure under blower boost (boost compensation). While it is not necessary to connect a hose to the vacuum/boost compensation port, it may be beneficial in some cases. However, the small plug on the barb must be removed before use.You can mount the 4305M regulator at any angle. For maximum efficiency, mount it as close as possible to the fuel injection system. DO NOT mount the regulator on or near exhaust manifolds. A bracket is provided for convenient mounting.
      The 4305M parts include in this kit: 1 Fuel Pressure Regulator,1 Bracket,2 Bracket Mounting Screws,2 3/8" NPT Pipe Plugs,2 AN-8 Fittings,2 O-rings for Fittings. 
      The 4305M has 3 specifications.The first one is port thread sizes: 3/8" NPT and AN-8.The second one is adjustment range: 30-100 PSI .The third one is Fuel Application: Gasoline and Alcohol/Methanol.
      The 4305M has 4 informations about installing the 4305M regulator.The first one is connect the fuel line and the return line. The return line must be attached to the bottom port on the 4305M regulator. The fuel line must be attached to the upper -8AN port on the regulator. Fittings must be purchased to adapt the fuel line and the return line to the 4305M regulator. The unused port(s) in the regulator can be plugged or used as gauge port(s).The second one is turn the fuel pump on and check for leaks. If leaks are found on the NPT (tapered) fittings, make sure the threads are covered properly with Teflon sealer.The note is if the fuel system will not prime properly, back the adjustment screw all the way out of the regulator until the system is primed. Then reinstall the adjustment screw.The third one connect the vacuum hose that was originally connected is to the 4305M stock regulator to the small nipple on the Mallory regulator. This will reduce fuel pressure at idle and during light-throttle cruise.The fourth one is set the fuel pressure. Loosen the jam nut on the top of the regulator and turn the brass adjustment screw to adjust the pressure. Clockwise increases pressure.