Originally Posted by petesonhisway
Have you checked that the drain hose (the transparent one) hasnt become disconnected from the bottom of the air filter box?
I had similar symptoms to you last year and was convinced the head gasket had gone but it was oil blown through the crankcase breather hose that had run into the bottom of the filter box and run out onto the cylinder head because the drain hose had become detached.
Looked for all the world like a blown cylinder head gasket - I even stopped at a KTM dealer in Germany for a second opinion, and their mechanic - a beautiful little blonde girl with her arm in a plaster cast - agreed.
Checked the pipe Pete and all is good, it is leaking from the bottom of the cylinder.