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Turd Fuel Hose

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  • Turd Fuel Hose

    2005 F225 TURDS....

    Twice in the last ten hours of operation, I've had to pull the VST and clean the High-Pressure Pump's intake screen. Twice in ten hours. Good thing I don't pay a local mech to do my wrenching. The screen gets clogged with tiny black particles of crud and they mechanically block the flow of fuel into the pump. The first stage filter on the front of the engine is spotless.

    Therefore, that crap is only coming from the degradation of the inside of fuel lines downstream from the VST. That gets sloughed off and is then returned to the VST by the injection manifold and associated hosing. Those bits small enough to get through the screen eventually clog the injectors. Been there and done that. Getting ready to do that again.

    I am going to replace ALL of the fuel lines on the engines. Yamaha wants 40-50-60-70 bucks for EACH SHORT bent pieces of hose. We know that the engine is covered with them. So what, 500-600 bucks or so per engine for fuel line? Nuts.

    I am going to replumb all of the long hoses with aftermarket straight hose. I am going to run a pipe cleaner through the short (50 dollar) elbows and other shaped sections. If they come out clean and show on signs of internal erosion, they're going back on unless I can make a new, straight piece work in their place.


    Can anyone recommend the best source of aftermarket hose that is the proper diameter for these engines and can anyone speak to the suppleness of the hose?
    It looks to be 1/4 inch, but it doesn't say so on the YAM hose.

    ** As an aside, buy a set of used YAM (Bosch?) injectors for your engine on eBay. You can get a rebuilt set for less than one new injector from Yamaha. I keep a spare set and when I need them, just pop them and then send the old set off to Mr Injector for cleaning.
    Last edited by oldmako69; 3 weeks ago.

  • #2

    could it be brush dust from the pump motor?

    I am sure they are metric sized hoses
    Last edited by 99yam40; 3 weeks ago.


    • #3
      I suppose it's possible, but they look like little flakes of rubber. It doesn't appear to be dust. Pieces just big enough to clog the screen.


      • #4
        I believe the hose is 8mm - almost the same as 5/16".

        But as you've no doubt noticed,
        much thinner wall than "USCG approved" / "marine" fuel hose.

        "Automotive" fuel line is closer in terms of OD/flexibility/bend radius-
        but if you are talking about the hoses to the fuel rail and back -
        for that pressure, you need automotive 'fuel injection' hose
        (and Oetiker clamps)

        Last edited by fairdeal; 3 weeks ago.


        • #5
          Found suitable high psi fuel hose today at Oreilly. $2.99/foot.

          Educate me. Why Oetiker clamps? And,

          there are two fuel lines that run across the back of the engine. One takes HP fuel from the port side fuel injector manifold and delivers that fuel to the starboard FI manifold. The other returns excess fuel back to the VST. They have a fitting described as a "joint" in the Yam engine manual. Does anyone have an idea as to their function?
          Last edited by oldmako69; 3 weeks ago.


          • #6
            I always thought they referred to a piece of hose


            • #7
              oetiker clamps are one time use clamps and installed with a special pair of pliers....they work very well.

              You can buy "Fuel injection" hose clamps which can be removed and reused.

              Standard hose clamps you buy at the hardware store have a flat spot under the screw drive and may not seal or suck air under the higher pressure of fuel injection systems.


              • #8
                I don't see the benefit. I've run cars and boats for decades without them. Yam puts wire ties on some of the lines on the suction side and those idiotically hard to move springy things that just serve to lacerate flesh. Oh well.....


                • #9
                  Originally posted by oldmako69 View Post
                  They have a fitting described as a "joint" in the Yam engine manual. Does anyone have an idea as to their function?
                  The function of the "joint"?
                  convenience, nothing more
                  when un-installing/re-installing parts of the engine:


                  Last edited by fairdeal; 3 weeks ago.


                  • #10
                    Thank you for that. That's exactly what I thought. When you price out individual sections of hose you're up into hundreds of dollars at an alarming pace. I am going to eliminate those joints and just run a single section of Fuel Injection grade hose instead.

                    ***Just for grins I added up the hose prices and got to $677 per engine with a few of the hoses being labeled as "Unavailable".

                    Yesterday I pulled and cleaned the VST (dirty, again but not that bad since I only put about 3 hours on the engine) and pulled the injectors. I took long pipe cleaners and threaded them into the fuel lines. I then pulled them out and ran my fingers over them. While I didn't see any of the tiny black 'bits' that I've been removing from the VST screen, my fingers were solid black with the decomposing rubber. I have to think that I am on the right track.

                    93 here today, so I may wait until this evening to head back over. From 4pm on the boat is in the shade.

                    Thanks for the input. Will stop at Orielly and see about buying some fancy-ass clamps and pliers. AMZN will likely take too long.

                    Q. How does one loosen Oetiker clamps? Looks like you just jam a drift in there and wiggle it loose. But what I don't know is a lot. But I can get a VST cleaned in about 40 mins now, cowling off to cowling on.
                    Last edited by oldmako69; 3 weeks ago.


                    • #11
                      Originally posted by oldmako69 View Post
                      Q. How does one loosen Oetiker clamps?


                      • #12
                        Pretty much exactly as I figured!


                        • #13
                          So I bought some of the clamps and the tool. The first thing I learned about them is that after you cut the crimp to remove the old clamp, use pliers to remove the remnants. Those mothers are like mini razor blades! I christened my port engine with a lot of Type AB human blood when performing the work.

                          I replaced every hose on the pressurized side with the exception of the one that runs from the VST to the fuel pressure regulator. I also added a fresh set of injectors and replaced the racor filter. Curiously, the old one was only about half full of fuel when I removed it. I would have expected it to have been full to the brim. It's not leaking and there are no fuel vapors in the bilge. I just ran the boat a few days ago.

                          Some of the formed hose tight turns and curves were easily overcome with straight hose by simply using slightly longer sections to avoid kinks. Running them was a bit of a challenge in some cases. But I did not get a chance to run the engine as a massive storm rolled in right when I finished. This may have been an exercise in futility. Will post up the results.
                          Last edited by oldmako69; 3 weeks ago.


                          • #14
                            Hopefully that is the end of your fuel problems,
                            and you can enjoy the boat.

                            Originally posted by oldmako69 View Post
                            replaced the racor filter. Curiously, the old one was only about half full of fuel when I removed it. I would have expected it to have been full to the brim. .
                            I have no idea of the normal 'level' inside the steel canister filter,
                            since its opaque.
                            But the analogous translucent bowl, under the cowling,
                            is invariably only 'partly full'.
                            I've never understood how that is possible...


                            • #15
                              Given that the low psi lift pump only runs part-time at idle, I can envision the front, first stage engine filter bowl being less than topped off. You have varying levels of suction and feed. When you shut the engine down it's typically been idling for a bit. I dunno. Perhaps?

                              But the Racors are plumbed in a manner that only allows them to be full. The new fuel enters the filter at the exact same level that it leaves. So I have a hard time seeing it anything less than full. I only care because sometimes I have a hell of a time getting the bulb tight. For some reason, when I shut the boat down for an hour or so, I almost always have to re-prime the VST on one engine.

                              There was a slight amount of oxidation on the Racor housing where the element screws up to it. I feel as though this could allow a slight leak and make priming the engine difficult with the squeeze-bulb. I cleaned up the mating surface and applied a light coat of waterproof grease. Pretty certain that the fuel will eat it, but on the outer edge it may help stave off oxidation and corrosion. It was difficult to get it to prime. So I tried a bulb with better suction and was able to get it started. I also ordered two new bulbs.
                              Last edited by oldmako69; 3 weeks ago.