YBR125 motorcycle cylinder, cylinder diameter 54MM, size (including installation hole position, height) and YBR125 engine completely match, directly replace the original cylinder, no processing crankcase/cylinder head interface; The inner wall is processed by honing process, the surface roughness reaches micron level, and the piston/ring matching clearance is accurate, ensuring the cylinder seal and compression ratio, and the power output is stable; Aluminum alloy material + multiple dense heat dissipation fins, can quickly export the high temperature of the combustion chamber, avoid "cylinder pulling" failure, suitable for long-term high load cycling; The surface is anodized, resistant to fuel/oil corrosion, long-term use without cylinder wall corrosion, deformation.