31-05-2021, 10:51 AM
I suggest running the engine from a test tank hung from the central bonnet stay, gravity taking petrol to the carb. Obviously you would need to disconnect the fuel inlet to the mechanical pump. If the engine runs satisfactorily without petrol getting into the sump you will have proved where the problem is (the original pump?). I suggest that an old lawnmower tank may prove suitable for your needs.