G- Cylinder 50mm 81cc 2V Cast Big Bore Kit Duo Combo (139QMB)
Description: Cast-Iron Cylinder 50mm 72cc with Cast Aluminum Piston. The cylinder bore is 50mm. Cylinder 50mm 81cc 2V Cast Big Bore Kit includes the following parts 50mm (81cc) cylinder jug with cast piston and 2V 64mm height cylinder head. Cylinder 50mm 81cc 2V Cast Big Bore Kit is suitable for all air-cooled 4-strokes, 49-50cc Kymco engines (scooters), and most Chinese imported vehicles 49/50cc (scooters, quads, and buggies).
When used in conjunction with a stock stroke of 41.4mm the engine displacement comes out to 81.3cc! When used with a 44mm stroker crank, engine displacement = 86.4cc!
NOTE: Please, measure with a caliper 139QMB crankcase bore (opening) for 49.5mm cylinder outer diameter sleeve need a minimum 50mm bore clearance or boring and machining are required. If, engine case must be bored, order an engine bore tool (Part# 1400-1001). Most stock 139QMB cylinder head's valve height is 69mm which comes standard with its 69mm rockerarm. This Cylinder Head's valve height is 64mm and will work only with a 64mm rockerarm. If you need a set of 64mm rockerarm see Part# 151-101 sold separately.
Includes the following Cylinder, Base gasket, Piston, Rings, Piston pin, Circlips, Cylinder head, Head gasket, Exhaust gasket, Exhaust studs, and Intake studs.
1. Includes Cylinder 50mm 2V, Piston + Rings, Gaskets (base gasket, steelhead gasket), Wrist pin, and Circlips.
• 1x Cast-Alumin Piston: 50mm
• 5x Piston Rings: 50mm
• 1x Wrist Pin w/G-clips: 41mm x 13mm x 8mm
• 1x Cast-Iron Cylinder: 50mm
• Outer Sleeve Diameter: 49.5mm
• Overall Height (w/sleeve): 70.3mm
• Cylinder Height (w/o sleeve): 53mm
2. Includes Cylinder Head 50mm 2V NON-EGR, Valve Assembly.
• 1x Cylinder Head Stud Space: 50mm / H: 60mm / Intake Port: 17mm / Exhaust Port: 18mm
• 2x Valves: 18.4x64mm Intake / 16x64mm Exhaust / Stem: 5mm
• Overall Height (w/valves) H: 66.1<67.3mm
• Cylinder Height (w/o valves): 59.5mm
• 2x 6mm Intake Studs
• 2x 6mm Exhaust Studs
• Fit Intake Studs: M6 / Nuts: M6 / Socket: 10mm
• Fit Exhaust Studs: M6 / Nuts: M6 / Socket: 10mm
• Fit Rocker Arm Assembly: 64mm / Feeler Gauge: .004in / .005in / Socket: 9mm
• Fit Cylinder Studs: 168mm 176mm / Nuts: M7 / Washers: M7 / Side Bolts: M6 / Socket: 8mm-10mm
• Fit 50mm Stud Spacing /Diagonal 70.5mm
• Fit Crankshaft 41.4mm to 44mm
• Fit Dowel Pin Set (8x14mm)
• Fit QMB 49/50cc+
Supported Models: 139QMB 49cc-50cc engines, Baja SC50, Boreem (BMS) 50, Filly 50, Kymco 50, Panterra 50, Qingqi 50, QLink 50, Roketa 50, SUNL 50, SYM 50, Tank 50, TaoTao 50, and virtually any other scooter engine with these measurements.
Item Weight & Product Dimensions:
• 1.456 Pounds | 4.567" (L) x 4.275" (W) x 2.776" (H)
• 2.193 Pounds | 5.227" (L) x 5.323" (W) x 2.598" (H)