Tractor Repair: Old Ford tractor runs 40 seconds, then stops, float chamber, ford tractor

Question
I have removed fuel filter (half dome glass with screen under fuel tank) and flushed gas tank with fresh gas, cleaned line going to carb.  Starts up easily, runs ~ 40 seconds, then stops.  Won't restart until sits ~ hour. Then repeats.  Could this be carb problem?

Answer
 Subject: Old Ford tractor runs 40 seconds, then stops Question: I have removed fuel filter (half dome glass with screen under fuel tank) and flushed gas tank with fresh gas, cleaned line going to carb.  Starts up easily, runs ~ 40 seconds, then stops.  Won't restart until sits ~ hour. Then repeats.  Could this be carb problem?

HI TRENT
You have done the right things .Yes it seems to be taking this long to get through! It would seem that it runs for a short time but only using up fuel that is in the float chamber!
Witch suggests that fuel is not getting to the float chamber and re plenishing the used amount. If the fuel line is clear and the filter good. This may indicate that the float is sticking in its closed position –needle high in its recess check that the needle sits in its hole correctly and is not jamming in its closed position.
The other thing is if you have only put in a couple of pints of fuel then this may not be enough to get out of the tank –try putting a couple of galloons at least in!
Martin