First try at fixin' would be to drain the gas outta the tank and lines and put in a new filter. Old gasoline just won't do the trick.
If ya still cain't get 'er to run smooth, your fuel pump may have gone south. Fuel pump innards like carburetor innards can be cantankerous--'specially ones that have been settin' around for a spell.
If you start getting a bunch of crud in the new filter, a tank cleanout may be in order.
