summary:

the tractor was running ok. It ran out of fuel. The problems started after you refueled.

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My first impression is your spare gas can may have contained some dirt, or leaves, or perhaps water. Look in the fuel tank for signs of contamination. Remove the fuel hose from the carburetor to take a fuel sample.

If contamination reached the carburetor, you may have to clean this.

Bluemower may have the basic or perhaps a contributing cause of your problem . One other point have you inspected the fuel line from the tank to the pump for a fuel filter ? It may require cleaning or replacement . Another good suggestion after inspecting the fuel tank is also to drain it and add fresh fuel along with some concentrated fuel cleaner , this may preclude need to dismantle carb . Otherwise ensure fuel pump is pumping fuel to the carb by removing fuel line prior to carb .