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doubleh2

lawn mower not working

doubleh2
11 years ago

my Briggs and Stratton lawn mower engine was running rough. I checked the oil and it was low, so i added oil. I was concerned b/c I had just checked the level last week- and it was fine. That got it started for a minute then was running rough, then not at all. i opened the air filter on the carburetor and a lot of black gunk in the carb, had the consistency of oily dirt. i scooped out about 1 tbsp and cleaned out the carb with a rag, put some drops of gas in, and no luck. is this engine dead? I don't want to pay the shop $75 for them to tell me this.

thanks

hh

Comments (9)

  • bill_kapaun
    11 years ago

    What's the MODEL & TYPE#'s of the engine, so we can identify which carb it has.

    IF you scooped out THAT much dirt, that's NOT a good sign. How much went through to the cylinder/piston???

    A "few" drops of gas isn't enough. Use a couple teaspoons worth.

    Also check for spark to make sure it's not an ignition issue. You might want to pull the spark plug to make sure it's not covered in "crud".

  • doubleh2
    Original Author
    11 years ago

    Thanks Bill! the engine decal is missing, but I have a pic attached.

  • bill_kapaun
    11 years ago
  • doubleh2
    Original Author
    11 years ago

    i looked at the link, examined the whole engine, not to be found. i do have some more info. I cleaned the spark plug and it fires (tested). I got the engine started w/ the filter off so i could see the carb. a mix of oil and gas is coming from the fuel line. Also, yesterday, I looked under the deck and saw some nylon rope biding the shaft, not i had to cut it free, ti was wrapped around the blade as well. i'm worried that this distressed the motor and blew a gasket or ring.

  • rustyj14
    11 years ago

    UUHHH, that carb does not have a fuel line! It pumps fuel up from the tank that it is bolted onto. What you think is the fuel line is actually a tube that sends excess gasses back to the carburetor!
    Where the carb bolts to the fuel tank, there is a rubber gasket, that acts as a pump to send fuel up into the carb. Make sure that gasket is ok. any tears, folds, or other things might give you problems.

  • bill_kapaun
    11 years ago

    Did you overfill the oil?

    The hose Rusty described is a crankcase vent hose. It allows excess combustion gasses (blow by) to be "recycled" into the combustion chamber.
    Too high of an oil level can cause foaming (amongst other things" and can be carried through the vent hose.
    It CAN also potentially blow a gasket/seal because pressure "might" build up, depending on how overfull it is.

    A side view pic of the carb may be helpful.

  • doubleh2
    Original Author
    11 years ago

    thanks for the feeback. ok, I disconnected the crackcase vent hose and the motor works fine. There is a small amount of oil coming from the vent hose, not much (a few drops a minute) but enough to make the engine sputter. Attached is a side picture. I don't think this is the serial number but it on the side of the motor. ybsxs158va 274460

    thanks
    HH

  • bill_kapaun
    11 years ago

    ybsxs158va 274460 is the smog label.

    That's a flat head motor, so a blown head gasket wouldn't "pressurize" the crank case.

    Either the rings are badly worn, allowing excessive combustion gasses past them (which "escape" to the crank case) or the oil level is TOO full.

  • rustyj14
    11 years ago

    NOTE: The proper way to check the oil is:

    1. Remove stick, wipe it clean, then put it back in its hole, all the way, and then pull it out again. This gives the proper reading of the oil level!
    2. The oil in the engine can and will stay high on the stick even after it has been shut down since last week, or last time it was run. Thats why i say to do it the way i do it.
      I have an old Toro Wheel-Horse, with a 10 hp Briggs on it. I hadn't run it for 3 weeks, but did start it up yesterday. Before starting it, i removed the dip-stick, and it had oil on it, about 6 or more inches higher than normal!. After i wiped it and re-stuck it, i found the oil to be at the correct level. But, if the oil is real low, the dip-stick can still read higher than it should.