Join Date: Jan 2004
Location: Sterling Heights, Michigan
Did it just show up one day or was it something that's been getting progressively worse over a period of time.
There's really only a few things that would cause this. The most obvious is something rubbing on the painted surface like a key FOB or tag, but you're telling us that didn't happen. Someone else mentioned heat, that's a big possibility, you should investigate what's behind the cover. You know how car hoods and roofs get that white, chalky look from being exposed to extreme heat from the sun? That's the clear coat being damaged and might be the same thing that's happening to your side cover, but not from the sun, instead the heat source might be from behind the cover.
One other thing that could be causing it is some type of chemical or corrosive fluid that found it's way onto the cover. Probably not as likely but still worth checking out to see if you have any leaks.....
1973 Yamaha RD-350
Sterling Heights, Michigan