Briggs 12.5 Opposed Twin Carburetor

JT Britt · May 25, 2012

Briggs & Stratton 404707-0122-01 12.5 opposed twin cylinder.Has 3 bolt fuel pump carburetor 399229 brass float.Do these floats set parallel to the carburetor top?This is where it was set when i got it.Thanks

rrobert · May 25, 2012

I would try making the float level with the carb top and see if it runs better. Bend the tab with a small screwdriver. It should run like that. It has a deep carb bowl.

Remove the float and shake it to make sure there is not any liquid inside the float. If you hear liquid, replace the float.

What is the problem you are having?

JT Britt · May 26, 2012

Robert it is running lean,and won't idle.Runs good at full throttle.I have soaked the carburetor overnight in solvent.New needle,and fuel pump kit.

Anonymous-0 · May 26, 2012

1. Solvent is not carb. cleaner. You may have to invest in the correct stuff.

2. I would bend the tang that closes the needle so that the float is level. That is the way almost all carbs. are set.

3. Those carburetors usually respond to cleaning the main jet. Its behind the plug on the lower side of the carb. If it won't come out with gentle use of allen wrench or screwdriver just clean it right where it is with a small wire, a torch tip cleaner or some such and spray carb.cleaner.

4. Sometimes the problem is the secondary jet, it can be seen through one of the holes at the top of the main body. It is a little brass cup with a tiny hole in it. Clean it the same way.

5. If your carb. had an idle mix screw, remove it, clean in behind it with spray carb cleaner.
It may be that opening the idle mix 1/4 to 1/2 turn will solve your problem.

JT Britt · May 26, 2012

Set the carburetor float to parallel and it works just fine.Thanks guys.

Briggs 12.5 Opposed Twin Carburetor

JT Britt

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Anonymous-0

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JT Britt

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