need to determine if it is a problem with the internal engine , safety switches, fuel related, ignition.
check to see if there is spark by using a spark tester. check the compression of the engine. yes it can be checked even though it has a compression release system. compression should be 50-60 psi maybe more. if these are good, then it is a fuel issue.
when you cleaned the carburetor, did you remove welch plugs? did you chase the passageways with a soft wire? if not, there is probably still an issue inside it.