Why I take things apart even if they look good.

I wasn't in a hurry to change the oil on the R100/7 but I didn't like the way the clutch system was and I noticed some red colored, rubbery stuff around the oil filter cap that I didn't really like so I removed the cap, the red stuff, O-ring and filter.  Right away I noticed that the metal washer that is normally between the cap and O-ring was missing,  also noticed the filter had not been changed in a long time and everything was sludged up so after I drained the oil pan I did a rinse-down of the oil pan too.  After reassembly and topping off with fresh oil I ran the bike for about 5 minutes and checked the level.  Everything looked good so I went on and did the drivetrain flush and resupply.  Here is a photo of what I took out and reinstalled.

Very cold today, with rain and icing conditions, so I did not have a chance to get on the road.