Hello John, Eric is correct there is a pick-up tube that reaches to almost the bottom of the tank and suction from of the fuel pump draws fuel to the engine. If you need to bleed your system it may be easier than you think. You’re also correct that the fuel filters have to be full before you bleed but unless you ran the fuel out of the filters there’s probably enough to get the engines started. I have a 42 aft cabin with Cummins 903 naturally aspirated diesel engines and they are very easy to bleed. The fuel pump is on top of the engine in the valley, (they are V8 engines) on the forward part of the fuel pump is a bleed screw. I just open that bleed screw and turn the engine over (this works better with two people) and when the fuel starts flowing I close the bleed screw and the engine runs just fine. If you often find yourself bleeding the fuel system then there is air being sucked into the fuel lines before the fuel gets to the pump. There are a few fittings between the tank and the pump and it should only take a few minutes to check for any loose fittings. Something else that you may have noticed is that there is another hose or tube running from the engine back to the fuel tank. That is called a fuel return hose and that returns unused fuel to the tank. Why have so much extra fuel flow from the tank that it has to be returned? The answer is that these engines are designed to use that extra fuel flowing through internal parts to act as a coolant and lubricant. There’s also a residual benefit from the return hose. Having fuel returned to the tank allows you to decide where that fuel goes. On you 42 there should be a series of ball valves with fuel and return lines running to and from them. This allows you to take fuel from one tank and return it to another therefore changing the weight distribution of the fuel. By moving fuel around while underway you will be able to control list, attitude and trim of your boat. Transferring can only be done while the engines are running unlike other fuel transfer systems which use electric pumps dedicated to the task. All the best, Bernie Southern California 1973 42 aft cabin Cummins 903
-----Original Message----- From: john hitchcock <[email protected]> To: unifliteworld <[email protected]> Sent: Sat, Apr 7, 2012 6:10 am Subject: [UnifliteWorld] uniflite 42 ft question 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 at http://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.
