well first you need to find out what is causing it to slip. check and see if the clutch is properly adjusted. check the clutch arm on the shifter side of the case and be sure the two arrows (one on the tip of the arm one on the case) line up properly. then be sure ur cable is adjusted. if the two arrows arent aligned then search for how to adjust the clutch arm. if they are aligned and the cable is just worn its time for a new cable. if both of those things are ok then you may need to replace the clutch discs and springs