1996-2005 Suzuki DF40, DF50 Four Stroke Outboard Service Manual, Page 72Get this manual
3-17 ENGINE CONTROL SYSTEM FUEL PRESSURE REGULATOR The fuel pressure regulator is located in vapor separatorThe regulator' function in the system is to maintain constant fuel pressure relative to the injector while the engine is operatingThe regulator diaphragm chamber is open to the vapor separator chamber to keep the pressure balancedFuel pressure, adjusted by the regulator, is constantly maintained higher than the pressure in vapor separator chamber by approx255 kPa (2.55 kgcm2, 36.3 psiBy-pass fuel is returned back to the fuel vapor separator chamber
VALVE CLOSED (below 255 kPa)