I'm having the same problem with my customers bt80. It's just slow take off if any take off and feels like it's always slipping. It's says to add oil to it (haven't the slightest idea why since it's cent clutch) people tell me use normal 10w30. Being a motorcycle tech, adding car oil into ur bike is among the most blasphemous thing u can do right next to spitting on your mother and driving a scooter so I decided to go with 2stroke oil instead. It's works alright maybe 12mph out of it but I know it's capable of more. It's gotta be. Average rear sprocket not to big or small. Could be, am I supposed to run it dry? like my intuition is popping a synapse screaming at me to do? Or perhaps gear oil? Or hell why not brake fluid? Or mineral oil? With normal wet clutches the oil lubricates bearings, keeps the engine clean and keeps it cool. Well with this application is not doing any of those things; grease keeps the bearing rolling, the gas keeps it cool, and the oil in the gas keeps it lubricated. I cannot see the point of oil in the clutch