i have an older exmark 48 inch manual 5 speed walk behind with a kawasaki( yeah i know) engine. the problem is, is is all of the sudden QUIT wanting to start. It started fine and ran great all day until i reched my last two proerties. It is pull start, and on the first of the last two properties it took about 20 pulls to start it. then on the last property i could not get it started and i have checked everything i can think of shy of tearing the engine apart. changed the plug and filters, and to no avail it still will not start. can anyone help me?