It could be from someone putting something in your oil while you was in the gym. What's the correct way to check the oil on that bike and what was the last thing done to it (from washing it to adjusting the suspension)?
The correct way to check the oil is to have the bike on both front/rear work stands so that the bike is level
- not tipped over on the side stand. The bike should have been left alone for a few moments since last having the engine operating - allowing the oil to drain from the top end. There are two horizontal lines cast in the case at the sight window. The oil level should be between the two lines.
Yet, one more reason to invest in safety wire and respective specialty pliers and optional plastic tubing, and a few small drill bits.
Now I don't know Dean93
's character, but since he's on a 636, I'll give him the benefit of doubt, and say he's a fine upstanding member of his community. Thus, has given no one just cause to perform nefarious acts upon his treasured bike. But, it goes without saying, there are any number of sociopaths in any community who have no need for cause in order to do shitty things to good people.
BTW, if I were a betting man - which I am not, I'd say Dean93
's problem are not dino-juice contaminants.