NCY Cylinder Kit 4T (81cc, Iron, 50mm); 139QMB cam Stem Inner Diameter: 23mm

Stem Inner Diameter: 23mm

Scooter Platform Installation Requirement Honda Ruckus (NPS50) Requires aftermarket Handlebar Stem/Clamp Yamaha Zuma (Pre-bug & BWS) Direct fit for most 7/8" clamps Honda Grom / Kawasaki Z125 Standard 7/8" clamp compatibility Custom Mini Bikes Coleman

Maintenance Note: If you ever damage a peg while off-roading

Durable Construction: Built to handle the heat and friction of high-RPM riding

NCY Cylinder Kit 4T (81cc, Iron, 50mm); 139QMB cam Stem Inner Diameter: 23mmNCY GY6 50 139QMB 50mm bore Cast Iron Cylinder Kit w o head. The perfect upgrade for most 4T 139QMB GY6 50 scooters, this bolt on 81cc kit will really give your scooter some go. It is recommended to get part number 1100 1239, 50mm big valve head as well, as most stock heads will not fit. In addition, we really recommend 1100 1250, NCY Performance Camshaft as an amazing complimentary item to this kit. It will allow the kit to perform to its maximum