After a day in the baking hot garage the bike is working now. At first it only gave a little burp, but that was more than this morning. After a few more burps I tried Mountaintime's advice and just held the throttle open and cranked. More & bigger burps followed, then it finally roared to life. Thanks for the good advice, Mountaintime. I took the bike for a spin to make sure everything was dried out by wind or engine heat.
BTW, there was no blockage in the front cylinder spark well drain. So I don't know where the moisture was.