Lawn mower pull cord not engaging flywheel

I have a simple murray push mower with briggs and Stratton engine. I was having issues with it starting probably due to using leftover gas in can from fall and cleaned carburator and after placing cover back on the pull string now pulls with no resistance like its not turning the flywheel to attempt to start. When i was turing lawnmower back over the stop bar came off so i put that back on and reinserted the cable so would that have anything to do with it? Like the stop cable does pull back the brake when i pull back bar but wont let me try to start it. If the cable is not coming bacl far enough to release the flywheel brake will the pull string still pull freely? Please help! Cant really afford a new mower currently:(