JD 2020 problems

Discussion in 'Shop Talk' started by caseyweiss, Dec 15, 2006.

  1. caseyweiss

    caseyweiss Well-Known Member

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    Location:
    ohio
    I have a John Deere 2020, wide front, gas, with a JD 37 loader. It is a great utility tractor and I use it almost everyday. It has some problems with the carb and/or the throttle system. It has been running very rich and using alot of gas. I will take the adjustment pin out of the carb and squirt some carb cleaner in it and it will idle slower, but the next time I use the hand or the foot throttle, it seems like it gets stuck open again. When it gets stuck open, it will spit out some black smoke. Any suggestions? It only has 2200 hours and was rebuilt about 200 hours ago. It was rebuilt because one of the piston sleeves was really tore up and scored.

    Thanks,

    Casey
     
  2. moopups

    moopups In Remembrance

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    In beautiful downtown Sticks, near Belleview, Fl.
    There are two things I would look for in this case, the first being a clogged float chamber vent, located at the top of the float chamber. If the air in the chamber cannot escape it will be compressed causeing the fuel to be pressurized enough to flow into the jet and then the venturi of the carb, causeing too much fuel to enter the combustion chambers.

    Second thing is the float's level, it should be parallel to the same surface of the carbs bottom when held level. This is the point that shut off of fuel happens correctly.
     

  3. farminghandyman

    farminghandyman Well-Known Member Supporter

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    Make sure the bowels and passages are clean, (not sure if that is a MARVEL-SCHEBLER), but on my old tractor I got some rust particles in it and it would run and then not run and would run rich, I cleaned it and tried a gain , fought it for over a year, finally I took it off the tractor and to the shop and got the air blow gun on and worked ever passage and it has worked well since,
     
  4. agmantoo

    agmantoo agmantoo Supporter

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    A rusty/trashy fuel tank will contaminate the carb and create the problems. In older tractors I like to have a fuel filter in line to the carb. You may have an already existing original filter but the screen probably is not sufficient to do the filtering task. I think the fuel is not being shutoff with the float as there is trash in the seat area thus causing flooding(black smoke). A neat way to determine the fuel level in the carb is to remove the plug in the bottom of the carl and install a barb fitting. On the barb fitting affix a short length of clear tubing and turn the tubing up and tie it in place to where it is vertical. The level of gas in the clear tubing is the same as what is in the carb bowl! You can run the tractor and observe the tubing to determine if the fuel level remains constant.
     
  5. boonieman

    boonieman Well-Known Member

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    I have an 8N Ford that once did something similar. Turned out that the sahft for the choke butterfly was broken, but you couldn't tell it from the outside of the carb. The durn thing would flop around inside the carb, going open then closed, then open again. It was tuff to find. Anyway, just something you might check.