Topic: CB500 won't start when wet/moist! Need help!

[ApolytonJS]

Hey everyone!

This is my first post on the sohc4 forum, & I appreciate all of you for viewing it. This is my problem: I've owned a '72 CB500-Four for ten years now, and since I've moved to San Francisco, the motorcycle will not start whenever it's foggy out (which is 95% of the time where I live.) I store it under a tarp, but the dang thing just won't start. When left out in the sun to dry for a few hours, it'll start no problem.

Last year, I was able to ride the bike in the pouring rain without a problem, at least initially. I've replaced the condensors, several gaskets, spark plugs, & spark plug caps, all to no avail. I'm at a loss of what to do, so any suggestions/advice would be greatly appreciated! Thanks so much guys:)

-Jonathan

[RAFster122s]

Try replacing the coils or coil wires, as you may have electrical breakdown of your plug wires.
WD40, Wire Dryer#40, may be able to help you diagnose the issue.  If the wires are original or very old, it can be a likely weak link, and will help in general terms by providing a better spark path.  If that doesn't help, then it is time to ensure your electrical system isn't getting compromised by the wet, so clean, tighten loose connections/connectors and coating with water displacing products like conductive greases or dielectric grease may be in order.
Change one thing at a time to isolate the cause...that is recommended.