**Verify the part fits before purchasing** Specs: Description: Cast Replica Stroker Piston Kit Compression Ratio: 9. 2: 1 Cylinder Bore: 84. 000 Piston Diam: 83. 940 Displacement: 381. 00 Size Over STD: 1. 00 Notes: Stroker Performance piston kit; 1mm makes 381cc. Must be used with Hot Rods stroker crankshaft 4143. Kit includes: Piston, rings, pin, clips Fits: Yamaha YFM 350 Raptor 2004-2011, YFM 350 X Warrior 1987-2004