briggs 20 hp runs for about an hr then shuts down

Thanks for the add.

I recently (5-20-19) picked up an white gt 2055. it has a 20 hp b&s horizontal shaft. It will run for roughly an hour and then shut down, couple cranks and it starts for a few minutes more and repeats. sometimes it sputters and slowly dies, other times it shuts down like you turned the key off. I have went through the carb, and added a piece of pop can between the float and needle, without it would puke gas out the breather. it has new filter, fuel line. closed cap or open it does the same thing. most of time when i have taken the air cleaner off to look down the carb, it is dry, a few times there is gas started to puddle. I did just put some rings and other items in, so the outside is clean and should eliminate the idea of overheating. Any ideas would be greatly appreciated. Thank you

Well first of all the pop can piece should tell you there is a carb problem. I’m thinking the needle and seat is leaking or the float is cracked with fuel in it. The needle and float regulate the amount of fuel in the bowl. If the needle Is leaking then the engine floods out with too much fuel.

I will try a new needle, but after it shuts down, if its flooded shouldnt there be a puddle in the carb?

It’s probably flooding the cylinder. See if plug is wet after it shuts down.

Carb needs to come off & come apart to be properly cleaned.
Then you need to rig up a high fuel tank, the higher the better and hook it up to the carb without the float bowl so you can work the float with your finger & check if it is cutting off the fuel and also passing enough fuel.
Go mow the instant the mower stops ( if it still does stop ) pull the line off the carb and crank the engine check for fuel flow.
Debris in the fuel tank can accumulate in the outlet which forms a plug slowing down the fuel flow

ok this is what happened late yesterday and today 6-21. yesterday i ran it just outside till it died. I think took the carb off and took the bowl off so it would still hold the gas, there was not much in there. I took fuel pump off and cleaned that, there was a lot of silicone or gasket maker in there. That however didnt help until i made the fuel as short as possible and that helped some. I did take the tank off a few days ago and cleaned the inside real good.

when the carb is off i put a clean hose to fuel supply blow in and air passes through until i tip it over then it shuts of. I have also done it with the bowl off and worked the float and it shuts off. I also polished the seat today. with out the piece of pop can on float to push the needle a little more it pukes gas out the breather. with it on it wont come out the breather. however either the pump is not keeping up or the float doesnt allow enough through and while working it just cant keep up. I will take look at the spark to see if its wet tomorrow, and also try a new pump.

With that piece of soda can wedged in there the float won’t sit at the right angle or work properly. I’m assuming it’s angled downward and won’t allow the bowl to fill to the proper level. You can “Jerry rig” many things on a mower but the carb needs to be right.

GOT IT, it was the fuel pump, one came in yesterday late, got it in this morning and so far so good. Thank you all for all of your insight.