BR starts and dies

Hello, my excellent running hand-crank two-cylinder BR suddenly has begun dying after firing several times and running between 15-20 seconds or sometimes up to a couple of minutes. I think it's starving for fuel, but the carb has plenty of gas in the bowl when I open the drain and the tractor will start after sitting a few minutes. Does this sound like a sticking carburetor float or what else could it be?
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Condenser in mag may be shorted out.

The moment it dies check that you still have a good blue/white spark at both plugs that jumps a 1/4 inch gap or more. If you do then

#2 open the carb drain plug and let the gas flow. It should fill a pint jar in under 3 minutes

If the carbs needle valve is sticking/hanging and not staying open enough to keep the bowl full, it wouldn't have "plenty of gas in the bowl" as you describe. However, that's NOT to stay there still couldn't be a fuel restriction other then the bowl and needle valve assembly. It still has to suck gas up into the throat via venturi action and other jets and fuel passages. Sooooooooooo it could still be a carb problem even though its not the needle valve.

To be safe and verify if its an ignition or a fuel issue when she dies, you need to verify if when she dies its still producing a spark ?????????? Its not hard to quickly pull a plug wire off a plug maybe 1/4 inch or so and crank her over and see if its sparking or if possible a coil wire subject to what ignition you have. If she's still firing good but cant keep running I suspect a carb problem but if she dies cuz theres no spark, I suspect the points or condenser or a cap n rotor problem or even a coil. Condensors are known to only go bad once warmed up and so are coils.

You gotta see if its dying for lack of fuel or lack of fire, from what you say Ima thinkin its a carb or fuel flow/delivery problem, even if NOT a bowl or needle and seat issue.

If you turn the gas on and open the carb bowls bottom drain cock see if it will run a constant continuous steady stream of gas at least the diameter of a lead pencil lead????????????? If NOT (slow or weak stream or it dont flow constant and steady), there could be a restriction in a fuel filter or sediment bowl or the tanks bottom outlet where rust and crud accumulates.

Next I would remove the gas line where it enters the carb and see if there's a good steady full constant flow there??? If not again it may be a clogged sediment bowl assembly or a clogged filter or the tanks outlet is clogged up or the gas lines clogged.

CHECK AND CLEAN THE SEDIMENT BOWL AND ANY FILTER AND INSURE GOOD GAS FLOW OUT BOTTOM OF TANK INTO SEDIMENT BOWL. Some sediment bowls have a mesh screen up top that can be dirty and some bowl assemblies get gunked up so even if there's good gas flow out of the tank its NOT getting thru the sediment bowl then down to the carb.

John T

How long has it been since the tractor last ran and what grade of fuel did you use in it? I have been having issues with any tractor that has sat for a year or more with regular grade fuel. I will no longer run any gas that contains ethanol in any of my antique tractors it gums up the carburetors badly.

It sounds like you are getting just enough flow that to start the tractor but not keep it running. Even if you are getting good flow to the carb you could have some build up around the needles not allowing enough gas to the engine when running. Will it rev up or just idle. I had to pull the carb off an AR recently and clean the scale out, for the cost of a few gaskets some carb cleaner and a little elbow grease it was well worth it.

I rebuilt the distributor and I don't think I really needed to, but it wasn't that expensive. I do have an unstyled AR that had a combination of fuel and spark issues, fuel is solved but still no spark from the mag.