unstyled B carb seat

A friend has an unstyled B. The carb is flooding the cylinders. The float is good and has the correct height adjustment.It has a new needle and seat but still does it. I have heard that you can put in a Briggs and Stratton needle and seat for better sealing. Has anyone done this and if you have what part numbers did you use? Thanks.

Really look closely at the area where the gasket for the seat sits in the casting. Sometimes they need resurfaced and sometimes the hex part of the seat itself needs camphered so it doesn't bind up in the recess so the gasket can seal. If you have a metal needle set it in the seat and LIGHTLY tap it so as to seat it in the seat.

I know this is not what you asked but things I've seen & encountered in my past cause me to ask...

Are you experiencing a slow leak as in it slowly leaks out of the tank into the engine over night or is this a big time fuel overflow pouring out whenever you turn on the fuel? I can't really tell from your message.

If it's the slow leak, don't even bother to read on!

If it is the big time overflow filling of the cylinders, usually this is caused by one of two things. Either the float is hitting part of the center core of the assembled carb or it has a plugged fuel bowl vent in the main carb body.

If the float is hitting something, you need to realign the float in the bowl before installing the bowl on the carb. A thin smear of grease on the float & inverting the assembled carb may help by transferring grease to the contact point if there is one.

If it's the vent passageway, air trapped in the fuel bowl must escape when the bowl fills after the fuel is turned on or the incoming fuel will run right up the main fuel nozzle & into the engine. Usually if the bowl vent is plugged it is clogged by "winged mud bearing critters" that got in while the carb was off or when the inlet elbow from the air cleaner was off. In either case, it likely just needs a real good cleaning. That MAY however require drilling out those passages! The pupal carcases and silks left behind won't be dissolved by cleaners & the silks can stick real well inside those passages.

Some ways you can tell if it is the vent is to leave the fuel bowl gasket out between the bowl and the body or maybe just leave the bowl loose. Fuel will leak out the bottom if you do this so be careful of fire. Another option (my personal favorite) is to install an old gasket with a small chunk (less than an 1/8th of an inch) missing then turn on the fuel. If it does NOT over flow in these conditions, it is likely the fuel bowl vent and you then know what to fix.

Have chased & caught that rabbit before!

Later.

are you sure your float doesn't have holes in it. take it and shake it or put it in a pan of hot water and see if it spits at you. you'll have to hold it down under the water and don't get burnt.