There is a idle adjustment screw on the carb turn it in 1/4 turn at a time until it ticks over.
Willo
July 2013
There will probably be two jets in the carb,a SLOW RUNNING jet and a MAIN jet,the slow running jet operates at tickover and the main jet works at higher throttle openings.The slow running(or PILOT jet)could be blocked.Try cleaning the carb.Also make sure the air filter is clean as it may have a problem drawing air in.