81cc, Iron, 50mm NCY Cylinder Kit ; QMB139
NCY Cylinder Kit (81cc, Iron, 50mm); QMB139: Automotive. Buy NCY Cylinder Kit (81cc, Iron, 50mm); QMB139: Rebuild Kits - ✓ FREE DELIVERY possible on eligible purchases. Take your 49cc scoot up to an amazing 81cc for Maximum Power! . Add top and bottom end power . Does not include head . High Performance, Manufactured in Taiwan by NCY . GY6 50/QMB39 50mm bore Cast Iron Cylinder Kit w/o head. The perfect upgrade for most QMB39/GY6 50 scooters, this bolt-on 8cc kit will really give your scooter some go. It is recommended to get part number 0-239, 50mm big valve head as well, as most stock heads will not fit. In addition, we really recommend 0-250, Performance Camshaft as an amazing complimentary item to this kit. It will allow the kit to perform to its maximum potential and go 50-55 MPH! Have a look at our Decompression Tube Assembly (0-282) which replaces your dipstick and allows excess crankcase pressure to be released. Good idea to install one of these alongside any cylinder kit upgrade. . . .