The vac connection on the carb should be blanked off otherwise you draw air in and get a weak mixture - and it pinks
But be careful one stump is the vac connection the other is the float chamber over flow, the engine will die if you blank that off - just pipe it away safely.
But be careful one stump is the vac connection the other is the float chamber over flow, the engine will die if you blank that off - just pipe it away safely.