Learning carburetors

  • Linux

    So I was chatting with Nicholas tonight about my carbureted engine issues, and figured others might want to follow along.
    I’ve done some engine work on EFI car engines, but really didn’t understand carburetors very well. I’m starting to figure it out…

    The cup, which is what fills with gas, and sat with gas in it all winter. This brown goop is bad bad bad.


    From where the cup would be, looking up. You can see the gasket a bit, and it’s a rubber Oring type, so hopefully I can replace it easily if needed. It seems to be in OK shape though…


    Nicholas says BE CAREFUL or you’ll lose the tiny spring and be mad. So I’m careful…


    The top hole is where the needle sits. I need to get a better look to see if it’s gummed up.

    The bottom hole is the jet, I think?

    The black flat piece is like, a whole sheet of gaskety stuff. It’s in rough shape, and the gaskets themselves smell like gas, so I’m hoping this is the leak point for the fuel leak…

    Anyway, I’m just learning as I go, and appreciate @Nicholas 's help as well as any observations etc from the forum. If anyone has questions or wants pictures, let me know. I don’t know enough to teach, but I can take photos so someone else can explain :)

    Learning and working on learning more!


  • Linux

    So if hypothetically one strips the jet screw and has to replace it, are they hard to find? :(

    Learning and working on learning more!


  • Linux

    Depends on the carb I guess - what car/carb are we working on? Now, be sure the cast housing is not stripped. Leaks could be a major issue and a stripped housing is likely irreparable. Jets tend to be brass (in my carbs anyway, and the housings are general less strong)

    Have a photo to look at?

  • The bottom hole under the needle and seat is the jet. That is most likely plugged up and causing the problem. When it is removed, if my memory serves me there is a couple other brass pieces underneath. If it is stripped it may cause some problems. I am not sure if you can get a new jet. I assume you stripped the slot for the screwdriver as it is hard to find a screw driver that fits correctly. Your leak is most likely the O ring on the float bowl, the drain plug on the float bowl or the line going into the carb. The gasket is a bit buggered up but probably hard to replace. I would try maybe try leaving both pieces untouched and using copper spray gasket. Make sure to avoid getting it into the carb or the head. Before you put it all back together spray brake clean through any passages you see and and make sure they are clear. Avaoid getting it on rubber parts as it will dry it out. Hope this helps.

  • Can you post a photo of the stripped screw? I might be able to make you a new one if you can’t find a replacement.

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