61mm Big Bore Cylinder Kit for 150cc GY6 4-stroke engines. Upgrades to 169cc based on a stock stroke of 57.8mm! Includes cylinder, piston, pin, circlips, rings, head gasket, base gasket and chain tensioner gasket.

You may need to modify your engine case to accommodate the larger cylinder.

• Upgrades to 168.9cc!
• Bore: 61mm
• Overall Height: 90mm 
• Cylinder Sleeve Outer Diameter: 63.7mm

Please Note: Does NOT fit 161QMK “200cc” engines!