I had the same thing happen as @slovcan did. My dirt bike, granted clutches get abused in the woods, started slipping soon after using some quality car oil. 10W-30 if I recall. I tried the oil change route and my clutch still slipped.Is anyone here aware of any modern clutch issues using an energy-conserving oil with friction modifiers? I know what they say will happen, but what actually does happen?
I pulled the clutch and the fiber disks had glazed. I roughed them up with sand paper and reinstalled them figuring a new clutch was on the horizon. I don't believe I ever had to fix it again though......
Some car oils are OK but are not marked MA. The "energy-conserving" part is what to avoid.