Carb flooding no matter what I do...

[Jml]

Lots of good suggestions here. I've found going from easiest to hardest works best. Check to make sure the choke is actually coming off. Check the spark plug to see the condition. Replace it. Be sure the gap is correct. Check for clogs in the breather or anywhere else. Check to make sure linkages are on correctly and moving properly. Check where the gas is coming from - back through the carb or in from the breather hose. Check the valve clearances. I've set a bunch of these Brigg's engines and gotten them to run great again.

I had an engine that was blowing gas back out the carb. Turned out to be caused by the aftermarket carburetor. Used the good bowl of the new car on the old carb and she purred like a kitten.

 

[ccheatha]

As anyone who's had flooding from their carb, the first thought might always be an old needle sticking, but with a new carb that should not be the issue. I've had old carbs sticking like that and I'd just tap the bowl while running and that would free it up then, but you knew you had to pull it apart to clean it up properly. It'll be interesting to see what you come up with in the end. I love taking something that doesn't work, troubleshooting and fixing - that's satisfaction. Best of luck with it.

 

[slomo]

but with a new carb that should not be the issue

New means nothing. Seen several new parts be dead in the box.

 

[tagpop]

Whenever I have flooding I watch the oil level to insure gas is not getting into the oil, oil will be overfull. When you open the cap to check the valve clearance is it dirty, rusty; turn the engine several times and insure the valves are working freely lube with wd40 or something similar. I have two of these old engines and still appreciate the flat head design.

 

[ccheatha]

New means nothing. Seen several new parts be dead in the box.

I guess anything's possible, but I'd think it'd be rare to find a new needle/float assembly that's sticking right out of the box.

 

[Rivets]

Not as rare as you might think.

 

[Beamster]

Old Brit bikes were notorious for carb issues like that.
At a certain point they figured out that the modern gasoline ate away at the plastic floats and they would not float, causing the extra flow of gas and it ends up pouring out.
Suggest you replace the float and float needle and seat whether they look like they need it or not. They should be cheap enough and would require it sooner or later.

 

[MowManMow]

Check your oil level ASAP, pull your spark plugs out and turn it over to clear cylinders out. Do this with your fuel shut off or fuel hose pinched to stop the flow. Sounds like the old carb leaked fuel into the engine, most likely from old needle/seat going bad from ethanol fuel. Old rubber in them swells up and the needles stick open allowing engines to fill up with fuel. Hope this helps..

I'll just add, if engine itself is not full of gas I'd be leaning to a bad head gasket on it.

 

[SamB]

As anyone who's had flooding from their carb, the first thought might always be an old needle sticking, but with a new carb that should not be the issue. I've had old carbs sticking like that and I'd just tap the bowl while running and that would free it up then, but you knew you had to pull it apart to clean it up properly. It'll be interesting to see what you come up with in the end. I love taking something that doesn't work, troubleshooting and fixing - that's satisfaction. Best of luck with it.

It's maybe not necessary to add this,but just recently my 4 stroke outboard Yamaha was flooding over just as this instance here. Sometimes flood over,sometimes not. A very experienced engine(I thought I was @ 72!) mechanic told me to always run the carb dry to keep the needle tip away from the seat. Keeping the carb bowl full for weeks on end will 'ring' the rubber tip,resulting in possible not sealing properly,resulting in the intermittent overflow. He said I didn't need a kit,just a needle and bowl gasket. End of story,this fixed the intermittent overflow issue.

 

[NPD_GrayBeard]

With that much spitback, I would suspect a leaking intake valve. On compression, air is forced back into the intake manifold. The reversed air flow through the carb causes the fog of fuel spitting out of the carb. Check for a wet spark plug as one of the cylinders is not firing. Check compression to verify leaking intake valve. If low compression, check valve lash on leaking intake valve. You could have a stuck valve or the valve seat or valve face is worn. You will have to remove the head and remove the valve to set lash. Check valve seat and valve face for wear. Clean deposits off of a stuck valve stem and guide. Recut seat and replace valve if they are worn.