In the missus' Smallport Levin, it has massive hesitation and surging while revving, even under quite low load.
Does it most with about 1/4 tank of gas, but isnt too bad with lots of gas or very very little, weve done the fuel filter and every other usual thing. Which only really leaves Fuel pump or possibly a big build up of gunk i nthe bottom of the tank or blocking the filter net on the pump?
Any suggestions on things to try?