When I shut off the engine ( 17.5 Hp Troy Bilt mower) it of course spins a bit until it comes to a compression stroke then stops. Go to try to start again and it will not go through that compression stroke acting as if the battery was low or starter is weak. If I spin the engine back a bit so that it has a running start coming to the compression stroke it will get passed it and start. New battery and starter. Any ideas?