Amazon.com: Trkimal GY6 150cc Cylinder Head Assembly Valves(57.4mm) for 157QMJ Engine Scooter Moped ATV Go Kart Quad (Non EGR Type) Together with Gaskets, Spark Plug and 4 Studs : Automotive
Scooter 150cc Big Bore Racing Cylinder Kit for SYM Symphony Sr125 Orbit 125 Jet 4 GR Arab XS 125cc 57.4mm 4 Stroke| | - AliExpress
Cilindro Honda 150 SH/@/NES/DYLAN/Pantheon Airsal
57.4mm Big Bore Cylinder Kit Piston Set For Engine Gy6 150cc 4T Scooter ATV Dirt | eBay