Announcement

Collapse
No announcement yet.

OT: White globs of snot-like gunk in mower carburetor?

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • OT: White globs of snot-like gunk in mower carburetor?

    Fixing a MTD "yard machine" low end mower (no, I did not buy the POS).

    Only runs with gas dripped onto the air filter, so has a carb problem. Carb gets gas in float chamber. All parts seem to be plastic including the carb, so far.

    Inside the carb, and blocking the main jet, I found white globs of gunk. Bright white, with the general appearance and consistency of partly dried but still soft snot. If poked, they squash and stick to the plastic carb, but they can be hooked-out intact with a piece of wire. pieces of gunk vary from 1.5mm down to maybe 0.5 mm in general size.

    Jet was blown out, more than once. Gas changed, tank washed out.

    No idea where they come from, but would like to know, since they seem to re-appear and re-clog things, even though the carb and gas hose were cleaned out. Tank has a filter that will NOT pass anything near that big.

    There are white nylon-looking parts in there, the float, and some other small parts, but the globs do not appear to be from them, since all those parts seem to be hard despite being submerged in gas, so even if they brought in some shavings,they would not seem like this stuff. They have been washed off and have none of the gunk on them, as far as I can tell.

    Anyone run into that kind of gunk before?
    1601

    Keep eye on ball.
    Hashim Khan

  • #2
    I have seen white caked-on residue in the bowl of dried out carbs. That might've at one time been snot-like.

    Did you check the fuel line(s) after cleaning tank/changing fuel? Maybe some globules lurking in there.

    Comment


    • #3
      Try putting a sample into a small jar of fuel to see if it grows.

      Comment


      • #4
        and maybe check the source of the fuel, maybe it's contaminated?

        Comment


        • #5
          Many years ago I had a disaster rebuilding SU carbs - didn't have gaskets so I used silicone seal. Long, stringy, soft gunk everywhere. But as I recall it was opaque/clear, not white.

          Suppose the mower's DPO used silicone? (Some formulations are fine with gas, but not the vinegar-smelling stuff.)
          There are no stupid questions. But there are lots of stupid answers. This is the internet.

          Location: SF Bay Area

          Comment


          • #6
            "To see if it grows....." Could be, I suppose. Dunno what grows in gasoline and does not stick tight to surfaces... most of the pieces are loose, and able to slosh around. Only sticks a bit if pressed against the surface, and does not stick well.

            Tank and lines clean, as far as I can see. Pieces could not have come through the filter screen in tank which does not seem to have any extra holes. Size of pieces is odd, as if they were coming from inside, or were being created there.

            No clue where the stuff came from. Would help to know, of course, as it would be easier to eliminate.
            1601

            Keep eye on ball.
            Hashim Khan

            Comment


            • #7
              I'm betting on ethanol gas that sat too long. I've seen similar gunk from that in small engine carbs, but usually greenish, not white. That could just be dye in the fuel though.

              Ethanol in the gas is bad stuff for small engines, especially if they sit for long periods, like mowers, weed eaters, etc. I pay extra to buy straight gas for all of my small machines like that.

              Comment


              • #8
                Originally posted by Yondering View Post
                I'm betting on ethanol gas that sat too long. I've seen similar gunk from that in small engine carbs, but usually greenish, not white. That could just be dye in the fuel though.

                Ethanol in the gas is bad stuff for small engines, especially if they sit for long periods, like mowers, weed eaters, etc. I pay extra to buy straight gas for all of my small machines like that.
                This one is specifically marked to indicate it is OK with E10, which is what you can buy at any gas station. (by comparison, my truck will take E85). "Being OK with" does not necessarily mean it is not going to potentially cause trouble, of course.

                I have seen whitish powder when gas of various types has evaporated. This is different, white when in the gas, little 1mm or so particles. I did notice that when they thoroughly dry out, they will crush to a powder, still white, that is somewhat like wood ash. That suggests more similar stuff to the regular "gas gunk".

                Anyway, cleaned it out, jets are open, carb still not doing its job (although it gets gas OK, and float works), so I have more work to do.
                1601

                Keep eye on ball.
                Hashim Khan

                Comment


                • #9
                  Originally posted by Yondering View Post
                  I'm betting on ethanol gas that sat too long. I've seen similar gunk from that in small engine carbs, but usually greenish, not white. That could just be dye in the fuel though.

                  Ethanol in the gas is bad stuff for small engines, especially if they sit for long periods, like mowers, weed eaters, etc. I pay extra to buy straight gas for all of my small machines like that.
                  My guess is ethanol gas too. The greenish color usually comes from the brass jets. On a cheap plastic carb there may not be any brass jets. I've seen plastic and alum. jets on some of these pre set, non djustable crap carbs.

                  JL......................

                  Comment


                  • #10
                    Originally posted by lynnl View Post
                    I have seen white caked-on residue in the bowl of dried out carbs. That might've at one time been snot-like.

                    Did you check the fuel line(s) after cleaning tank/changing fuel? Maybe some globules lurking in there.
                    That's what I was going to say. Also the filter in the tank would still have had gas past the screen already that could have globed up. It doesn't need to sit more than a winter to go bad. Is there a separate filter on the gas line? Maybe that has crap in it.

                    Your machine is okay to run on it, but not to sit with ethanol gas in it. That stuff is horrible for small engine machines.

                    I'd love to know where Yondering gets gas without it. I'm actually on my way to the shed now to clean the carbs on two Honda quads. They ran fine last year when they were put away.

                    I wouldn't normally recommend any product that claims to clean your fuel system as most of it is BS, but I have actually had some success with 'Mechanic in a bottle'. Drain the tank again (no reason not to save the gas if there's no crap in it) and loosen the screw under the bowl to drain that and the fuel line. Work this stuff directly into the carb as much as you can by dumping it straight into the carb via the fuel line or the whole bottle into the tank. When it starts to come out the drain, close it and let the bowl fill up. Crank it a bit opening and closing the throttle and choke and let it sit for at least four hours. Overnight is fine. It won't damage anything. Don't drain it from the tank after you let it sit, just fill her up again. No guarantees at all, but just might save you from taking it all apart again. It definitely helps with poor running engines, I won't say it will get your's running again. I used it on my weed whacker a couple weeks ago. I could barely keep it running playing with the choke, throttle, etc. I dumped a bunch of it in the tank and in less than ten minutes it was running great.

                    Nothing beats opening the carb and cleaning out the jets with a carb cleaner and some compressed air. I use the tiny file set for clearing the hole in my mig.



                    Last edited by Jigs; 06-24-2017, 07:12 PM.

                    Comment


                    • #11
                      Don't eat it!

                      It's probably a fungus. It starts in the tank from water saturated alcohol in the gas then travels throughout the fuel system. The water will separate and sink to the bottom of the tank. Flush the tank, lines and clean out the carb. If the carb was allowed to dry, the float valve will need special attention. Fill with fresh gas treated with Sta-Bil and give it whirl.

                      Comment


                      • #12
                        Seafoam is another good one.

                        Comment


                        • #13
                          Does it looks like the white snot like substance you sometimes find in valve covers? That is the result of water in the oil making an emulsion. My WAG is that there are (very) tiny drops of oil in the gas (it's anybody's guess as to the source, could be from the refinery even) and since E-15 gas likes to suck water vapour out of the atmosphere, there is just the right amounts of water and oil in the gas to make that emulsion.
                          Location: Saskatoon, Saskatchewan, Canada

                          Comment


                          • #14
                            There is the possibility that after mowing all that grass and weeds it has allergies
                            Last edited by rolland; 06-24-2017, 07:32 PM.

                            Comment


                            • #15
                              Agree the people probably let gas sit in it. He's a PHD/MD and ought to know his organic chemistry, but his specialty is viruses, not gasoline or mowers.

                              Anyway, I mowed my lawn with it, it's working, and working rather well. Did not use the MIAB, but I've seen it and will note that (have used seafoam). Didn't use anything of that nature.

                              Inside this carb is a plastic jet assy that snaps into an oval stem about 3/8" x 1 1/4" or so, held by a snap on each side. There are brass jets in it, but they were not the issue.

                              I was able to pop out the plastic jet assy, and then pop the two parts of it apart. It takes a pocket knife and a 1/8" blade screwdriver to do that. You use both on one side , then the screwdriver alone on the other while the knife holds the first side open.

                              Then you use both, knife first and then screwdriver to pop the air bleed outer tube off the main jet tube.

                              There are air bleed holes in the main jet tube, which were full of a TAN deposit, pretty much like standard dry "gas gum". NOT the white stuff, which my not have had anything to do with the problem. Some tan junk was in the main jet tube, but it did not seem to be blocked. That was mechanically removed from all locations with some fine stranded copper wire, and the assembly was blown out again.

                              When reassembled, it worked as well or better than any of the other mowers here. First pull start, no hassles.

                              Not too bad for a POS.
                              1601

                              Keep eye on ball.
                              Hashim Khan

                              Comment

                              Working...
                              X