Yanmar 4BY2 Operation Manuals

Also see for 4BY2: Service manual

Contents

Filling the Fuel TankNOTICE: Operate bilge ventilation(blowers) for a minimum of 5 minutes topurge fumes from engine compartment afterrefueling. Never operate bilge blower whilerefueling. Doing so can pump explosivefumes into the engine compartment andresult in an explosion.To Fill the Fuel Tank:NOTICE: Only fill the fuel tank with dieselfuel. Filling the fuel tank with gasoline mayresult in a fire and will damage the engine.1. Clean the area around the fuel cap.2. Remove the fuel cap from the fuel tankfiller port.3. NOTICE: Hold the hose nozzle firmlyagainst the filler port while filling. Thisprevents static electricity buildup whichcould cause sparks and ignite fuelvapors. Stop fueling when the gaugeshows the fuel tank is full. NOTICE:NEVER overfill the fuel tank.4. Replace the fuel cap and hand-tighten.Over-tightening the fuel cap willdamage it.Bleeding the Fuel SystemThe fuel system needs to be bled under thefollowing conditions:• Before starting the engine for the first time.• After running out of fuel and fuel has beenadded to the fuel tank.• After fuel system maintenance, such aschanging the fuel filter and draining the fuelfilter / water separator, or replacing a fuelsystem component.The fuel feed pump is ECU-controlled andwill operate for only 10 seconds when thekey switch is turned ON while the engine isnot running or being started. For this reason,the key switch must be repeatedly turnedON then OFF to sufficiently bleed the fuelsystem.1. Turn the key switch on and leave on for10 seconds. NOTICE: NEVER hold thekey in the START position for longerthan 10 seconds or the starter motor willoverheat.2. Turn key switch OFF for 5 seconds, thenturn key switch ON for 10 seconds.3. Repeat steps 1 and 2 five more times.Note: The engine may run rough and misfirefor a few seconds when first started until anyremaining air is purged from the fuel system.4. Attempt to start the engine. If the enginedoes not start within a reasonable time,repeat steps 1 and 2 until the enginestarts and runs. NOTICE: NEVER usean engine starting aid such as ether.Engine damage will result.BEFORE YOU OPERATE24 BY Series Operation Manual© 2008 Yanmar Marine International