I removed the oil pan and found that the hole was for the oil pump overflow. there is a copper tube from the oil pump with an o-ring at both ends. The o-ring at the pan was leaking, hence it would weep just sitting as the oil level is higher at the bottom of the pipe. All better.
The recess is just beside the O2 sensor. I tried taking pictures, but it's in a tight spot. I've just ordered a gasket and will drop the pan. I'll post pictures when I get there.
I'm a new owner of a 2006 FZ1 with 4700kms. My first short ride, I could smell burning oil. After cleaning the oil pan up I found the source of the leak. It's a forged hole under the pan, like the one that has a bolt in it near the back of the pan. The oil is slowly seeping out onto the exhaust...
I cannot say a thing! I had just replaced both side fairings and front fender on my CBR1100 Super Black Bird, all OEM, back it out of the driveway, the earth became misaligned, and boom, dropped it. I sat and cried like Nancy Kerrigan.