Running for a minute means, to me, that the motor
started just fine but then died. Is this assumption correct? If so then I feel that there is some sort of fuel blockage and Chesapeake's suggestion that the vent may be blocked is certainly a good possibility.
Something else to check is your fuel pickup tube. Make sure that there is no screen
on the end that is at the bottom of the tank. If there is a screen
, remove it and throw it away.
Check that the fuel line is clear. With the pickup tube out of the tank and the line disconnected at the filter make sure that you can pass a wire through the tubing and that it comes out clean.
Check that the bottom of your tank is clean with no buildup of sludge.
I once had a situation where the motor
would start but would not run more than about 15 to 30 seconds. Turned out to be a clump of sludge lodged in the fuel line.