engine numbers would be helpful buttttt.... the perimeter of the recoil assy should be 3-5 small screws. remove them and it should come off, the is as long as you have a eagerbeaver engine ( tecumseh ohv )
Sounds like you will need to clean your carburetor.
Sometimes you can get by with priming it a few times, and letting it run a few times like that and it will flush the gunk out of the jets, but most of the time you will need to rebuild the carburetor. If the mower is over a couple years old, then I also recommend that you buy and install a new carburetor repair kit, because the diaphragm will get hard and that will cause it to be hard to crank. When you clean your carburetor and remove the jet screws, count the number of turns it takes to seat the jets from their original position. That way when you go to put the jets back in, you know how many turns they were in/out. Please do not forget to rate me, Thanks Good Luck, I hope this help