I'm new to this forum so please be patient ;-) I have a G10 (built 1977 I believe) with a Briggs and Stratton engine. It was working fine and then suddenly stopped starting. I replaced the plug and checked all visible leads for wear. The starter still turns over strongly but when I pull the plug and check the spark I get nothing. Any idea of a mostly likely cause for this? Solenoid maybe? It's a great little tractor so I'd like to get it fixed instead of replacing.