Motorcycle Repair: CL250S wont start when foggy, honda cl250s, dense fog

Question
My Honda CL250S failed to start after sitting in dense fog for several hours. After drying out overnight, it started first time. The thing is, it has never had a problem with rain. It's as if the rain runs off it but the fog manages to penetrate somehow. Any ideas what it is and what I can do to fix it, please?

Answer
Tom, that's new one for me.  It sounds like a high voltage leak in the coils, coil wires or spark boots.  The dampness will create a circuit to ground somewhere.  You are looking for a place where rain won't get to but the damp air can.  I'd start at the coils under the tank.  You are looking for a fine carbon track that will look like a crack or very fine black line.  

Regards
Rich