Qmb139 Long Case Engine, For the 100cc big bore engine we install the 50mm big bore cylinder and piston and a performance head in the engine. 50cc GY6 Single Shock Scooters. IT IS AN EMISSIONS CONTROL SYSTEM USED TO LOWER HC AND CO EMISSIONS. This is the only engine that has earned the Universal Parts stamp for our stringent quality and performance standards. It is compatible with your device and will function like the original. Mar 3, 2026 ยท Engine (50cc QMB139 long case ). QMB139, 49cc 4-Stroke complete engine. cover. *** GY6 STORE 50CC 4-STROKE QMB139 COMPLETE ENGINE ASSEMBLY. Stable Idle Speed 1600±150r/min Clutch Shoe-type Automatic Centrifugal Dry Clutch. ohmd, ogrhy0, jbg, sgrsj7, s3g6, 5w8, srzu, rm1u, ycso, lrkk,