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Unimog_404.113_1970
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Discussion Starter #1
Hi everybody!

I have bought carb. rebuild kits now, and i took some pics of the things in it.

Then i realised that i dont know what any of the internal parts are called ie.

I attach a pic with numbers on it, and if someone has a few moments of time perhaps you could post what the thing are called!

thanks!
 

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Fizz,

No 6 is the bowl needle valve actuated by the float, No 5 are needle valves for idle control, on the second picture the part with the spring is your plunger for the accelerator pump, the rest are an assortment of different sizes of jets and needle plungers to control the flow of gasoline.
It has been a long time since I rebuilt a carburetor and never owned a 404 but the principles are the same, in general those carburetors have five circuits, the float circuit, the idle circuit, main metering circuit, accelerating circuit, and high speed circuit, they are necessary since the flow of air can vary in a ratio of more than 100 from idle to full throttle, and fuel ratio needs to vary due to temperatures and speed and loads, like at cold cranking it needs to be rich and so at idle and under acceleration, the leanest mixture is about medium-medium high and a little richer at full speed.

It is important to set the float at their proper height so the bowl maintains a proper level of fuel, since you have a factory kit there is not much to do other than properly install the jets, they are already sized to specification, about the other adjustments you will have to do is set the idle needles and throttle opening for proper idle. (Since each carburetor is unique each has their own specifications so follow instructions furnished with the kit for additional settings)
I don’t know what actuates the choke in a 404 but that also has to be adjusted so the engine cranks easier when cold.

Inside the carburetor body there are small conducts drilled and capped that will supply fuel to the jets, make sure they are clean, sometimes it takes a solution to dissolve the varnishes that have been created by the gasoline and then blown by air pressure.

If your carburetor is properly cleaned and adjusted I assure you your engine will run properly provided nothing is wrong mechanically and you have a good ignition and timed right.
 

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Unimog_404.113_1970
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Discussion Starter #4
thanks!

i know how the carb. works .. they dont teach very much "mechanics english" in school though, so i dont
know what they are called ...

i can add two to the list!

5: Needle valve for idle (air och fuel) control.
6: Bowl needle valve.
 
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