Carb Cleaning, How to remove choke valve?

[JustinAlenScott]

Greetings Afourians and Carburetor Experts ^_^

I have a second Atomic 4 that I found for 100 bucks and while I am taking my time cleaning it up and rebuilding what I need to (I'll be wearing my learning hat a lot and my dunce cap a little) I am making use of some of the external engine parts for my running engine in the boat. Naturally I thought any carburetor problems I might be having might best be cured by swapping a newly cleaned up spare carburetor.

So now I am finding some of the effects from an engine sitting outside under a tarp for a couple months. Starting with the water I poured out of the carb when I pulled it off and we will see where else it got. The carburetor has a pretty nasty throat infection and I really need to clean this all out. I want to get the choke plate out and clean it thoroughly so that poppet valve doesn't get hung up. I pulled the screws holding the plate to the flat side of the shaft, but the plate is still retained by a clip around the shaft which now just spins inside that clip. I thought of course to remove the shaft, is that the answer? But after taking out a few screws from the arm and choke bracket it seems the shaft is retained somehow I cannot tell.

So here's my question. How is that shaft removed? Or how is the choke plate removed if there is a better way?

[Dave Neptune]

I would not recommend "ever" removing a butterfly off of a shaft as they are very difficult to set back properly, especially the throttle butterfly as they must be properly set. The "setting" is a big part of the idle metering at the idle ports and is very touchy. The choke butterfly is not as touchy as the throttle butterfly but is still a PIA even with well practiced hands.

Try to get it clean and moving freely first. Only as a last resort would I remove a choke butterfly.

Do poke the idle ports out with a small wire and use lots of compressed air. Also remove all jets and again use lots of air since there was water encroachment within the carb.

Another thing is be sure the float is set AND when set the float should be parallel with the carb body. I like the way these carbs work with a slightly "lower float level" than stock.

Dave Neptune

[roadnsky]

SOAK IT

Let it soak in pure vinegar for a day or two.
You'll be surprised at how much gunk will fall away.

Here's a pic of the float setting Dave is talking about. Very important.

[JustinAlenScott]

Thank you for the advice not to remove the choke butterfly. I'll get it put back together tlas straight as I can and try the vinegar soak. You think the vinegar might eat away the little bit of surface rust it looks like this choke valve has on it? Will it eat away anything else I don't want it to?

Special thanks to the recommendation of setting the float valve and the great picture showing me what I am looking for!

[JustinAlenScott]

This is my learning hat

When you say slightly lower float level, does that translate to a slightly greater than parallel angle which it looks like roadnsky has set in the picture above? And how does that manifest in the running of the carburetor?

[Dave Neptune]

Yes, when the float has a bigger gap "from the top" of the housing (bowl) the fuel level in the bowl will be lower. I set mine almost a full 1/16" more clearance for a lower (leaner) fuel level.

Dave Neptune

[roadnsky]

Quite a few years ago, Dave posted instructions for the float settings which I copied to use whenever I clean/rebuild my carb(s).
With credit to Dave (and hopefully his permission) here it is...

"When adjusting the float, err to the high side of the setting, which is a lower fuel level.

Hold the top half of the carb upside down with no gasket and the float installed, check the height with a scale (good ruler).
The factory setting is 1 5/32" to the bottom of the float, which is on top and resting against the needle which is resting on the seat.

Two things of import here...
1-Be sure the bottom of the float is parallel with the body (this controls the closing position of the float accurately) of the carb, or as close as possible.
2-When tweaking the tabs use a pair of needle nose or duckbill pliers.
DO NOT PUSH, PULL OR BEND the tabs by holding the float itself. Only hold the brass tabs.
Now you can bend the larger portion that attaches to the float for the parallel adjustment and the little tab that rests on the seat for the height.
This can be a bit frustrating so go slow and easy.
I suggest that if anything, you set the float a bit HIGH @ 1 3/16~1 5/32.
These adjustments are important to control the emulsion wells that mix air into the fuel to break it up!
The factory adjustment specs are 1 5/32 +/_ 1/32" which is why you need it to be as parallel as possible.
I run mine at 1 7/32 and like the way it performs."