The factory rider's manual (pg. 58) list Max. oil consumption at l/100km = 0.15 so you are still well below that. I agree the the recent increase should be investigated anyway. I would have to agree with chicken that change in oil formation that you are running could very well be the cause and very easy to check. I would try 20-50w non synthetic API SE and SF, the engine was not designed for synthetic and fear of developing sprag clutch problems with it's use. Also checking that the crank vent is not blocked is easy too. But in the end it could very well be time to move on to a different bike, I heard riding a K75 will "ruin" you!