Ok bc I've been running 80_90 in the 250 bc I had a blaster and my kdx the clutches were slipping with the lighter oil which was 10w30 and switched to the heavier and helped so I just ran it since but I didn't know it was bad for the clutches but it could be that it helped with those bc they didn't really put out much power anyways.I guess I won't take the jug.Can you use just regular motor oil or does that cause clutches to slip bc of the detergents in it? That's what I've heard which is part of the reason I switched to heavy oil.