I have a craftsman 15.5 hp rider and I was having trouble with starting it. I put a new solenoid on and it started and ran for a while, then it stopped suddenly. I thought that it was out of gas, but there was plenty. I put on a new fuel filter and that didn't work. I checked out the spark plug to see if I was getting a spark and there was no spark. I don't know what to do now. I would appreciate any help I can get. Thanks