As well as the other suggestions, constant pulling on the cord without the engine starting could flood the engine. If you have a socket remove the spark plug, if it's wet this is what's happened.Dry the plug and before refitting it to the engine, put the HT lead on to the end of plug and pull the cord, check to see if there's a spark at end of plug. If you have it''s not an electrical fault unless the gap on plug is incorrect, although if it's been recently serviced this should be correct.It sounds to me as if the carburettor has'nt been set correctly.