i posted about a week ago about dropping my bike at about 10mph.

tonight im tearing it all down and fixing everything. anyway the right rear set brake snapped so i took the exhaust and mid pipe off to get to all the parts better. when i took off the mid pipe where it sits level there was a small amount of oil residue on the end. it looks like it could have been gas mixed with oil. but it was dark and enough for me to take a swipe on my finger and look at.

could this be from the drop or is there something else that would cause this?

 

Chances are it is just carbon build up with condensation mixed in. The carbon build up will be black and wet due the condensation, and will have a nasty old gas smell to it.

If it is indeed oil, it may all depend on what did after the crash. If the bike sat on its side for a period of time, oil could have seaped into the cylinders, then if cranked the bike at all, it would have pushed the oil into the exhaust. It can also flow into the air box through the crank case vent, then into the exhaust.

I can't think of anything bad that would cause oil to be in the exhaust. Once you get it running, if it continuously smokes blue, then you have an issue somewhere. But after a crash, its not uncommon to get some smoke for a few minutes til the bike warms up for the first time.