B&S carburetor

[tractorguy2]

I got a free mower with a 5.5hp Briggs L head engine. I carburetor was a mess. I glass beaded it and put it in the ultra-sonic cleaner for hour and a half using full strength Simple Green cleaning fluid. I blew out all the passages I could and ran wire through them. I did not remove the welch plug on the side. Wasn't sure I had one to put back in. I checked to make sure the choke was working. Mower won't start without "liquid help" Found another identical carb in parts bin. Put it on and it starts on the second pull. I'm guessing I still have a passage blocked somewhere.

 

[Mule Meat]

Those carbs come in two verities.
One that works
One that doesn't

 

[560Dennis]

Take Welch plug out ( 2nd photo) of carb carb cleaner small holes . Use fishing line to make sure they are open , replace Welch plug .

 

[stevieb49829]

I got a free mower with a 5.5hp Briggs L head engine. I carburetor was a mess. I glass beaded it and put it in the ultra-sonic cleaner for hour and a half using full strength Simple Green cleaning fluid. I blew out all the passages I could and ran wire through them. I did not remove the welch plug on the side. Wasn't sure I had one to put back in. I checked to make sure the choke was working. Mower won't start without "liquid help" Found another identical carb in parts bin. Put it on and it starts on the second pull. I'm guessing I still have a passage blocked somewhere.

Is there a brass jet screwed up into the barrel that drops down into the bowl, or is the jet built into the brass bolt that holds the bowl on? Can you see light past that jet into the throat of the carb, or are the side holes in the brass bolt clean? That's the main flow of gas into the throat, and the most likely place to be plugged. Also, did you pull out the mixture screw and chase that with a wire into the throat of the carb? steve

 

[560Dennis]

I ve had success with ultrasonic cleaner if you have or borrowing one using dawn dish soap , on aluminum , look over the degreasers to see if compatible with aluminum .
Also had success with boiling with hot water and dawn dish soap aluminum carburetor.
Never had good luck with bead blaster, dust get into everything. takes forever to cleanse it out of the idle circuits
lets Us know what you find.

 

[T.R.K.]

Those usually gunk up the jet that is in the bowl nut. Most times the main nozzle stays open. Unless the mower can throttle down, usually there is not an idle circuit present. (Most mower engines are set up to run at one speed.)
also, be sure the inlet passage before the fuel gets to the needle is not plugged.

 

[timcasbolt]

I ve had success with ultrasonic cleaner if you have or borrowing one using dawn dish soap , on aluminum , look over the degreasers to see if compatible with aluminum .
Also had success with boiling with hot water and dawn dish soap aluminum carburetor.
Never had good luck with bead blaster, dust get into everything. takes forever to cleanse it out of the idle circuits
lets Us know what you find.

I've had good luck using liquid laundry detergent in my ultrasonic cleaner.

 

[tractorguy2]

Is there a brass jet screwed up into the barrel that drops down into the bowl, or is the jet built into the brass bolt that holds the bowl on? Can you see light past that jet into the throat of the carb, or are the side holes in the brass bolt clean? That's the main flow of gas into the throat, and the most likely place to be plugged. Also, did you pull out the mixture screw and chase that with a wire into the throat of the carb? steve

Main jet is in the nut.