2006-2010 Suzuki DF150 / DF175 4-Stroke Outboards Service Manual, Page 81Get this manual
ENGINE CONTROL SYSTEM
FUEL PRESSURE REGULATOR The fuel pressure regulator is located in the fuel vapor separatorThe regulator's 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 fuel vapor separator chamber to keep the pressure balancedFuel pressure, adjusted by the regulator, is constantly maintained higher than the pressure in the fuel vapor separator chamber by approx250 kPa (2.55 kgcm2, 36.3 psi)By-pass fuel is returned to the fuel vapor separator chamberVALVE CLOSED (below 250 kPa) VALVE OPENED (over 250 kPa)