I have a 17 go Troy-Built Riding Lawnmower, I replace the ignition and it did not come with a key. So, I went down and purchased a new key as well. After installing the new ignition, my lawnmower will not turn over. In fact, it does nothing when I turn the key. What could be causing this? I was told that this mower has several keys and it may not be the right key. But, the key goes in and turns like it should, only the motor does not turn over.