I have a MTD Yardman riding mower with a Briggs and Stratton engine. It will not start. First, I have just installed a new battery. When you turn the ignition nothing happens. I have checked all the wires and connections, but can't find anything wrong. It seems to me that it's got to be the starter, ignition switch, clutch switch, I just don't know what would be the most likely place for there to be a problem. I did find a fuse (20amp) off the wire to the battery but it was fine. Any suggestions before I have to take it to the shop?