Unable to start my self propelled lawn mower. the thin wire that pulls the choke had come off and I put it back on and now will not start. I love that lawn mower. what do you thin might be the problem?

A no start condition can be caused by several different things. A simple remedy to try is to remove the air cleaner from its housing and get some carburetor/choke cleaner spray and spray it into the air intake to the carb. Attempt to start immediately and if it pops, then spray some more. If you can get it to run, spray some into it while running...do this somewhere where it won't **** in dirt while running (in other words, clean the carb while its mounted on the engine). To really clean it the way it should be, it would need to be removed and soaked awhile in a bath-type cleaner.