Hi, I'm getting a GS, it's really nice bike and I have two questions:
After I test rode the bike, I found there is small amount of oil leaking off the gear lever. I did the research and realized that this is quite common for GS, and in most of cases it's just the grease coming off the chain lubrication. But my mechanic friend who is specialized in Suzuki told me it could also be crankcase gasket, sump gasket or shaft seal. I wonder in this case, how much it takes to replace them? (p.s. if the dripped oil is not hot, does that mean it's most likely the chain grease?)
Second, there is big white spot on top of the tank and owner said it was probably caused by gasoline done by his friend, (he sold the bike to his friend earlier but weren't able to collect the fund). I wonder if there is anyway to fix this issue other than repaint the whole tank.
other than that, the bike is in really good condition.

White Spot? Depends on what it is, never heard of gasoline doing that, but you know

Grease on the shift lever, if is cold and thick and very sticky then odds are that it is chain lube flinging off.

That white spot could be from the water repellent on a bike cover. I have removed that from a vinyl seat using alcohol but haven't really tried it on paint.

Thanks guys, I'm getting the bike tomorrow.