based on what you say now, would expect a dirty carb.
to test fuel pump, pull spark plug wire off, disconnect fuel line from pump to carb at carb. crank engine, catch pumped fuel in jar.
If good fuel stream, remove/dissassemble/clean carb using rattlecan carb cleaner and small gauge stiff copper wire to clean all orifices including jets. Blow same out with compressed air. Reassemble using new rebuild kit for that carb. Do not re-use old gaskets.
Also ck/replace fuel line(s) from carb to tank as needed. Make sure fuel filter is installed in correct direction.