Oil leak

After rebuilding the top end a few weak ago I've developed a new oil leak. It doesn't seem to be coming from the base or head gaskets, and the only oil is on the left hand side fins, and front of the engine. Not sure what to do.

A better pic of the head and barrels?
Steve

The yellowish spots are pools of oil sitting atop the fins. There's a small gap in the front where the head meets the jugs. Maybe that's part of the problem? There's also oil on the front of the alternator cover. Maybe the alt cover is leaking, and the oil is blowing upward and onto the fins.

Could be the tach drive or the O ring around the cam chain tunnel.
Steve

Makes sense that the o ring could have slipped up a little, and it would explain that gap. I did replace the tach seal but I'll take a look at it to make sure.

Hmmm, Looks like classic, cam chain channel O'ring leak to me.

I had one leak almost immediately. I now use a Cometic one piece head gasket. No leaks.
Steve

Me too. 3000 miles now and bone dry.

Yetanotherkzrider wrote: Makes sense that the o ring could have slipped up a little, and it would explain that gap. I did replace the tach seal but I'll take a look at it to make sure.

The gap between the head and cylinder block at the front (and rear) of the motor is equivalent to the compressed head gasket thickness, and is no reason for concern. My engine has no oil leaking from that gap.
Before doing anything else, I would wash off the leaked oil with an old gas dipped paint brush when the engine is cool, and observe closely for it to show up while riding. That will help you identify the exact cause without speculating.