I have two JD F1145 mowers one starts right away and the other acts like it is going to start right away but then have to crank it about another 5 to 10 seconds before it starts and then it emits black smoke when it first starts ( I always wait for the intake heater to cycle ) but it runs good the whole time it is running and I changed the fuel filter and air filters but still the same . After it starts it runs fine it almost seems it loses prime any one had this problem ?