Amazon.com: GY6 125cc/150cc Engine Upgrade to 180cc with Cylinder Head Valves and Rebuilt Kit, 61mm Big Bore kits with Piston and Ring Assy for 152QMI 157QMJ Engine Chinese Scooter Moped ATV Go
Amazon.com: 61MM 170-180CC Big Bore Piston Cylinder Kit For GY6 125cc 150cc Scooter ATV & Quad : Automotive
Amazon.com: GOOFIT 62.5mm Big Bore Cylinder Head Valves Replacement for 4 Stroke GY6 B 170cc 180cc 200cc 1P63QML Engine Chinese ATV Quad 4 Wheeler Go Kart Scooter : Automotive