34ich weber 1.3 starting problem

I've recently just bought a 1.3 driver was running fine until it started to splutter and cut out when I was accelerating so I thought straight away it would be the carb too the old silex carb off and replaced it with a weber I managed to get hold of one that had been jetted to a 1.3 engine , I fitted the carb up to the engine tried starting it but no such luck I've checked there fuels going in , the ignition coil , spark plugs were black when I took them out due to soles carb running rich should I change them ? Any help much apreciated ? Thankyou Tom