I went on a long ride this morning with my son up to Calaveras Dome. About 180 miles round trip. On the way up, when we would stop, I could see hot oil vapors coming up from the engine. I was hoping it wasn't overheating, but had a look at the left front of the engine and could see that it was leaking a bit of oil. It looked like this: It was only a little bit, so I figured I could deal with it when I got home. But I was wondering if I had a blown head gasket or some other gasket on the cam cover or something that wasn't installed correctly. I may have had one or two bad thoughts about my engine builder when thinking of what it might be. But after examining it a bit more closely I could see some shiny thing sticking out and touching the fuel tank. Time to take it off and see what it was. I was very relieved to see this: I grabbed an Allen wrench snugged it back up, and we're ready for tomorrow's ride which will involve a lot more dirt. I'll have to let the engine builder know that he missed one thing. Of course I also missed one thing - not installing the shift lever properly when I put it on to lift the engine into the frame. I only discovered that when I dumped the bike trying to turn it around on a dirt hill a couple of weeks ago. Both of those are fixed and the bike is running just great right now.