I do my own maintenance on my ATAS and have changed the oil filter twice. I have just been browsing my new Haynes workshop manual and I notice it mentions a check that I havn't done (on any bike I have owned). It asks you to check that the male thread that the filter screws onto has not partially unscrewed. There is supposed to be between 15.5 mm and 16.5 mm thread showing. Has anyone checked this and found it has unscrewed as the filter was spun off.