Eric is correct and John's question is valid because it would seem that having a gravity fed fuel system would work better, but then all the sediment would be sent through your engine and that's not good at all. I have Cummins 903 naturals on my boat and they are very easy to bleed. There's a bleed screw at the top of the engine in the valley, it's on the fuel pump. The few times I've had to bleed the engines I just cracked the screws open a little and turned over the engines until fuel started flowing from the screw. While you're still turning the engine over, tighten the bleed screw and the engines will run just fine. If the fuel lines have a cronic problem of air in them then you may want to check the connections from the pick-up tube to the fuel pump. If any of the fittings are loose, air will be sucked into your system and stop the engine. There shouldn't be too many fittings and should only take a few minutes to go through and tighten everything up..
Also John, note that you have another fuel line that returns to your fuel tank from the engine. That is called the fuel return line and it returns unused fuel back to the tank. You may ask, why send more fuel than the engine will burn and then return it back to the tanks. The answr is, it ensures that enough fuel is getting to the engines but just as importantly the extra fuel acts as a coolant and lubricant for components on the engine. On your boat you probably have a grouping of ball valves that have fuel lines running in and out of them. They are there so you can choose where the fuel is coming from and going to. If you need to transfer fuel from port to starboard or forward or aft you can open and close the appropriate valves to move the fuel around and transfer weight. Remember the fuel return line? You can pull fuel from one tank and return it to a different one effecting the boat's trim, list and running attitude. All the best, Bernie 1973 42' Aft Cabin Cummins 903 On Apr 7, 6:41 am, e b <[email protected]> wrote: > the supply outlet is on top of the tank but inside the tank there is a dip > tube that goes to the bottom, sometimes on the bottom of the tube thee is a > mesh strainer, usually the strainer and / or bottom of tube is slightly above > the bottom to prevent dirt / water from being sucked up if there is any. > depending on tank location / fuel level the fuel might be above or bellow the > engine the fuel pumps should have no problem priming the line unless the > check valve in the pump is dirty or sticking. > eric > > Date: Sat, 7 Apr 2012 09:10:02 -0400 > Subject: [UnifliteWorld] uniflite 42 ft question > From: [email protected] > To: [email protected] > > I have the above boat. The engines have not run in months but are in good > shape. Now that I am trying to start them I have a problem getting fuel to > them. I know I have to prime the filters but my question is...The supply > line comes from the TOP of the tanks, not the bottom. Therfore by the force > of gravity the fuel sould run back into the tank and leave a > airblock...right?? This would then be a constant problem. Anybody suggest > anything?? > Thanks John > > -- > > You received this message because you are subscribed to the Google Groups > "UnifliteWorld" group. > > To post to this group, send email to [email protected]. > > To unsubscribe from this group, send email to > [email protected]. > > For more options, visit this group > athttp://groups.google.com/group/unifliteworld?hl=en. -- You received this message because you are subscribed to the Google Groups "UnifliteWorld" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/unifliteworld?hl=en.
