Scooter Cylinder Block Kit For Jet 14 125 Jet X 125cc E5 12100-MB1-000 4-Stroke Engine This cylinder block kit is designed for use with Jet 14 125, Jet X 125cc E5 equipped with a 4-stroke engine.It includes all necessary components to replace or rebuild the engine cylinder assembly.The kit is compatible with models requiring 12100-MB1-000.Components are engineered to meet specifications for proper fit and function.Installation requires standard mechanical tools and knowledge of small engine systems. This is an independent replacement component.References to brands or models are solely for compatibility indication.