TBW1520 55.5mm Hight compression Lightweight Piston kit. TBW1521 130cc Top end Gasket kit. TBW1522 55.5mm TTR110 130cc aluminum steel sleeve Cylinder. Note - There are no installation instructions, but if you can replace your piston, you can install this kit as all the parts are installed in the same manner as the OEM parts.However, its highly recommended that a professional install this kit or, at a minimum, purchasing the shop manual for your bike available from your local Yamaha dealer. Furthermore dialing in the jetting and tuning a carb is also best left to a professional to get the best results. One size larger on the main jet and pilot jet is the recommended settings to start at.