Dear Arlen, Thank you for your input, but my emergency shut off valve is correctly set. I will check the lines but don't quite know how to check if it is sucking air. One very important thing I have learned with a diesel engine is that the starter motor has got to put out enough revolutions to start up, it is not like a gas engine which can fire up on half revs. It is just a job removing it in such confined space. Thanks for your input, I really appreciate it. John
On Sat, Apr 7, 2012 at 9:31 PM, M/V Arrluk Homer Alaska <[email protected]>wrote: > Hi John, > I have a 42' with twin 671's. They run great. My fuel filters are in > locations that are easy to get to and I think that previous owners > have upgrade the original system. I would suggest you do the same and > mount your filters in the engine room in a place were you can get to > them easily. > > As for your starting problem, I had a similar problem last year. The > port engine fired right up, but the starboard engine would crank over > good , and try to fire. I am a mechanic by trade (aircraft), but > don't have much diesel experience. After calling several friends that > do have diesel experience, I was told about the emergency air cut > off. If this valve is stuck closed, as mine was, the engine will not > fire up. > > This is an important part of a diesel engine and must be working > correctly. This would be your only means of shutting down a run away > engine. If a diesel engine goes out of control, it can actually > continue to run even if you shut off its fuel supply. This is because > it will suck its own oil supply and that is 5 gallons or better. If > your emergency air shut off vale is stuck, you need to fix it to were > it will work freely. > > Also, one time I had a fuel problem to the starboard engine. I could > not get the thing to fire and went through the bleeding process > several times. I finally found the problem was a cracked fitting on > the line going into the secondary filter. It was not leaking but was > sucking enough air to keep the engine from firing up. > > Thanks, > > Arlen Zacharias > 42' Sport Fisherman Extended Cabin > Homer, Alaska > > > On Apr 7, 2:58 pm, john hitchcock <[email protected]> wrote: > > Thanks EB and Bernie. I have the twin Detroit Diesel > > 6 71s and its a terrible job opening up the floors, and having to move > all > > the furniture to get off the fuel filters. Then I have had to remove the > > injector covers and brake them loose to bleed. I dont believe I have a > > priming valve or bleed screw as you mentioned. A problem Ive had in the > > past is that the port engine fires up immediately but the starboard just > > keeps cranking. I took in the starter and they found it was a 24 volt > > whilst my system is 12 volt.They corrected it to 12 volt and I put the > > starter back on but it still seems to be cranking slower than the port > > engine. Do you think this may be the problem why the engine wont start > up? > > > > On Sat, Apr 7, 2012 at 12:44 PM, [email protected] <[email protected] > >wrote: > > > > > > > > > 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. > > -- > 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. 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