Cylinder Kit - 72cc (Cast ); QMB139/GY6 49cc, (NCY Brand)
NCY GY 50/QMB139 47mm bore, Cast Iron, Cylinder Kit w/o head.
Our most popular big bore kit for the QMB139/GY6 50 scooter engine, this bolt on 72cc kit really performs nicely when you combo it with part # 1100-1250, NCY Performance Camshaft. Don't forget to upjet!
Have a look at our Decompression Tube Assembly which replaces your dipstick and allows excess crank case pressure to be released.
Good idea to install one of these alongside any cylinder kit upgrade.