Yooperdawg

Help! I Purchased an 86 Bayou 3 days ago and put a couple miles on it yesterday. It is in excellent shape showing very little use and did run great. Then the rain came down in buckets for an hour while I took cover. When the rain stopped it wouldn't start. I am experiencing the same exact problem, one spark when I release the starting switch with the spare plug shorted against the head. I haven't had time to dig into it but could use a direction. Any guidance would be greatly appreciated.