Carby gasket Bendix carby

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  • Merv
    Merv
    21 days ago
    What is this little curly spring in the lower right corner? I don't have one. What's it's purpose? When reading about or asked if I'm using the spring, I assumed the spring on the end of the needle was the subject. In the video Hilly gave me the link for, they say this : "il bet low is correct
    9 of 10 leaking bendix is due to incorrect helper spring install.
    one end of srring goes under the float tab (on opposite face of needle heel contact)
    AND OTHER END BEARS ON WALL OF FLOAT BOWL. it does not lie between bowl and gasket. "
    Which spring are they talking about?
  • Hilly
    Hilly
    21 days ago
    The one in the bottom right of that picture is the varmint in question and the one I ment, sorry I should have been clearer, it stops the needle from sticking shut.
    Check this out, watch the little videos, they make clear how it should work.

    IH: Carburetor, Intake Manifold & Exhaust - Sub-01L - Sportsterpedia https://share.google/uVOJCWnBxfeyEZzAj

  • Merv
    Merv
    21 days ago
    Quoting Hilly on 01 Oct 2025 07:54 AMedited: 01 Oct 2025 08:24 AM

    The one in the bottom right of that picture is the varmint in question and the one I ment, sorry I should have been clearer, it stops the needle from sticking shut.

    Check this out, watch the little videos, they make clear how it should work.

    IH: Carburetor, Intake Manifold & Exhaust - Sub-01L - Sportsterpedia https://share.google/uVOJCWnBxfeyEZzAj

    Ha! Thanks Hilly. Pity you are so far away. You have all the right info.
  • Hilly
    Hilly
    21 days ago
    Quoting Hilly on 01 Oct 2025 07:54 AMedited: 01 Oct 2025 08:24 AM

    The one in the bottom right of that picture is the varmint in question and the one I ment, sorry I should have been clearer, it stops the needle from sticking shut.

    Check this out, watch the little videos, they make clear how it should work.

    IH: Carburetor, Intake Manifold & Exhaust - Sub-01L - Sportsterpedia https://share.google/uVOJCWnBxfeyEZzAj

    Quoting Merv on 01 Oct 2025 08:27 AM

    Ha! Thanks Hilly. Pity you are so far away. You have all the right info.

    I'm learning just the same as you Merv, the only thing I knew before was there is a 3/16 drill bit method to set the float and don't mess the float spring up, I'd never actually done either but now I reckon I could 😁
  • Merv
    Merv
    21 days ago
    Hilly, that's a good link you have given to me. Some conflicting advice tho in the little section you mentioned about spring action. Of the 3 small videos, the first shows the spring action pushing the float away from the carby body (down), and the third shows it pushing the float towards the carby body (up). There's enough info there to explain the correct method of fitment tho. But I'm wondering why the spring is needed at all? It appears the correct installation would assist with the lift of the float to shut of the fuel supply. Does this mean the design has a float that's too small and not able to lift it unassisted when the fuel level is set correctly? I need to do more study. Reading it again, it claims the function is the opposite, so I guess I need to get my hands on an actual spring to study it closer. But with one end resting on the top of the float (under tang), and the other end bent downwards to rest against the side of the bowl, logic tells me the end under the tang would want to lift the tang. If the free end was rotated to rest against the top of the carby, I can understand the float end pressing down. I will re-read it a few more times.
  • Hilly
    Hilly
    21 days ago
    They worded that bit to cover the common misconceptions I think Merv, it is supposed to push the float away thus opening the valve, that is assuming the little clip on the valve is attached to the float properly so the float dropping pulls the valve open.
  • Merv
    Merv
    21 days ago
    What I can't understand is, it says the inwards pointing end of the spring sits on the 'top' of the float (white RH arrow in pic). So if I put upwards pressure on the other end to tuck it against the bowl wall (red arrow up), isn't the other end going to want to head towards the top of the carby? (blue down arrow). What am I missing here?
  • Hilly
    Hilly
    21 days ago
    Yeah it is difficult to picture like that, the vid 37 shows how it should perform with the spring in properly even though it is leaning on the gasket there, it's still installed right though as you are supposed to lift it up when fitting the bowl so the end of the spring rests on the inside of the bowl, vid 38 is just to prove that the float can overcome the spring force to close the valve needle when the chamber is full of fuel, vid 39 shows the spring incorrectly installed but the carburettor worked anyway, I assume that means the valve never got stuck shut and caused a problem, the wording isn't great but that's my take on it, without it in my hands that's the best I can make of it, you don't have a spring you said? Reading some of the stuff there it seems some reckon it's not needed and chuck it, probably where yours went.
  • Hilly
    Hilly
    21 days ago
    Found this on eBay, looking at the winding on it I can picture it working as explained, what do you think?
  • Hilly
    Hilly
    21 days ago
    Maybe in this perspective it will make sense 
  • Merv
    Merv
    21 days ago
    Look at the top center pic of the float on the inverted carby body. That bit of spring is quite clear. Now if, as you lower the bowl over the float, you were to lift that bit of spring so it rests on the wall of the bowl, there is no way on mother earth that the other end of the spring won't want to go in the opposite direction. That is, down. What am I missing here?
  • Hilly
    Hilly
    21 days ago
    I think, only think mind you that small end hits the upright of the float tab pushing back on it and if you take where the pin pivot is that would create a downward force on the float, you might be right Merv, you have a bugga to look at, I'm just trying to interpret what is written and pictured, maybe they have it all messed up?
  • Hilly
    Hilly
    21 days ago
    The spring is still in that carb you got off eBay, maybe it will become obvious when you get to look at it? Hope so anyway lol
  • Merv
    Merv
    20 days ago
    Quoting Hilly on 01 Oct 2025 01:24 PM

    The spring is still in that carb you got off eBay, maybe it will become obvious when you get to look at it? Hope so anyway lol

    That's great news, I hadn't looked that close. Will be easier hands on. I can see the need for it as viton tips are notorious for sticking when left for some time. Had one car where the only way I could get fuel to the bowl if left long enough for the carb to leak/evaporate dry was to unhook the fuel line and use the compressor hose to blow it off it's seat. Let you know when it arrives.

  • Merv
    Merv
    20 days ago
    I think the penny may have finally dropped looking at this illustration. Only one showing the actual location of the small end of the spring, but it's where you said it should be. I will use this spring, as the fuel level when set up with the 3/16 drill method, will be different with V without it. Thanks for staying with me mate.
  • Merv
    Merv
    12 days ago
    Ok guys, I got the new needle from the US a couple days ago, and the second hand carby top a couple days before. The second hand float is in good condition, with no holes when given the boiling water test, and I have been lucky enough to have arrived at a setting that just scrapes a 3/16 drill resting across the gasket. As a point of interest, the new float weighed 174.4 grains, while my soldered one was 174 grains neat, so not sure how relevant float weight is. 
    I decided to test the accelerating valve again, having studied up a bit and gained a better understanding on the carby workings. I sealed the hole in the bottom of the bowl with a couple rubber washers and a lightly tightened bolt, added some fuel to the bowl and worked the plunger, and at first I got bubbles out of the non return valve in the bottom of the bowl, however after a few plunges it worked as designed. I have carried out this test several times now, and whenever the valve is dry prior to adding fuel for the test, air always appears, however if fuel is left in the bowl, then retested an hour or so longer, it works good, so I'm happy with that. Might also explain why you might get a flat spot when first starting after the bowl has dripped dry.
    My next area of concern is the accelerating jet which sprays straight into the carby throat when the throttle is wrapped. Mine seemed to spray a stream of fuel that would make my garden hose feel proud.  I'm wondering if the engine accepted the spray without being swamped while in neutral because it could freely rev, however when trying to power the rear wheel the amount of fuel swamped the spark. The plugs were always very rich.
    The jet size is stamped 14, so I am now going to determine drill size for Bendix #14 jet and test it. If necessary I shall drop a spot of solder into the jet and re-drill it on my mill. Feel free to tell me how wrong I am anywhere above, or what I may have forgotten. Cheers, Merv.
  • Hilly
    Hilly
    12 days ago
    You are past my Bendix know how, I will be following along in learning mode 😁

    Edit, if you haven't seen it yet there is a site called Sportsterpedia, Google will find it, the information there is extensive, I just went and had a look at your carb, I think you would find it very helpful.
  • Merv
    Merv
    12 days ago
    Quoting Hilly on 10 Oct 2025 08:48 AMedited: 10 Oct 2025 09:01 AM

    You are past my Bendix know how, I will be following along in learning mode 😁


    Edit, if you haven't seen it yet there is a site called Sportsterpedia, Google will find it, the information there is extensive, I just went and had a look at your carb, I think you would find it very helpful.

    Yes, I have read it extensively since earlier postings and it is a mine of info. It gives a chart of jet sizes starting from #18 on, and back counting gives me a #14 size of .0276. But when I just run that by ChatGPT, it tells me that range of main jet sizes uses a metric numbering system, whereas the accelerating jet uses an inch based system, and #14 there is .014". Don't know how I existed without ChatGPT. I will get my micro drill bits out tomorrow and see what fits in the jet easily. I enjoy the chase. Will let you know.
  • Hilly
    Hilly
    12 days ago
    One thing I did see was that there is an oring around the main jet that can/does perish and fuel can then get past making the mixture rich, maybe that could be part of your sooty plugs scenario if you haven't been there yet?
  • Merv
    Merv
    12 days ago
    Quoting Hilly on 10 Oct 2025 09:47 AM

    One thing I did see was that there is an oring around the main jet that can/does perish and fuel can then get past making the mixture rich, maybe that could be part of your sooty plugs scenario if you haven't been there yet?

    Yes, new O ring in place.
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