Oil From Air Filter

I haven't looked into this yet but noticed a bit of oil coming out of the breather of our X1120D the other day. The oil level is good and it is running quite well.

I need to take the breather off and check the air filters to see where its coming from. But I wondered if this is normal or expected. It was about 30 degrees and I did let it warm up to two bars before I took off.

Any ideas?

probably your cranckcase vent is malfunctioning a little. on the valve cover is a small cover with a diaphragm and spring under it. probably needs cleaned.

That is where I will start, thanks very much.

Tony