My L130 "surges" once i take the choke off.. if i raise the choke to almost the fully closed position, it stops surging. the fuel pump is new. no gas leaks as the gas lines were replaced last year. i will admit to putting on a smaller aftermarket fuel filter. would that starve the engine of fuel? the fuel cap breather has also been checked and is clear. my engine is a briggs...thanks in advance for your help!!