Naraku Cylinder 52.4mm 94.9cc Big Bore Kit w/Cast Piston (139QMB)
Description: Naraku Cylinder 52.4mm 94.9cc Big Bore Kit w/Cast Piston for 139QMB 49/50cc+ engines. The cylinder bore is 52.4mm. Naraku Cylinder 52.4mm 2V w/Cast Piston including the following parts Naraku 52.4mm cylinder jug with cast aluminum piston. Naraku Cylinder 52.4mm 2V Big Bore Kit is suitable for all GY6 50cc air-cooled 4-strokes, 49-50cc Kymco engines (scooters), and most Chinese imported vehicles 49/50cc (scooters, quads, and buggies).
It’s also recommended to get a 52mm big valve head (Part# NK100.13) in order to take full advantage of the bigger piston valve notch. However, you can use the original stock cylinder head without any problem.
When used in conjunction with a stock stroke of 41.4mm the engine displacement comes out to 89.3cc! When used with a 44mm stroker crank, engine displacement = 94.4cc!
NOTE: Please, measure with a caliper 139QMB crankcase bore (opening) for 54.45mm cylinder outer diameter sleeve need a minimum 54.5mm bore clearance or boring and machining are required. If, engine case must be bored, order an engine bore tool (Part# 1400-1001).
100% Naraku Products – NO SUBSTITUTE.
Includes the following Cylinder, Base gasket, Piston, Rings, Piston pin, Circlips, Cylinder head, Head gasket, Exhaust gasket.
• 1x Cast-Alumin Piston: 51.86mm
• 5x Piston Rings: 52.4mm
• 1x Wrist Pin w/G-clips: 41x13x8mm
• 1x Cast-Iron Cylinder: 52.33mm
• Outer Sleeve Diameter: 54.5mm
• Cylinder Height (w/o sleeve): 53mm
• Overall Height (w/sleeve): 70.44mm
• Made in Taiwan
• Fit Intake Studs: M6 / Nuts: M6 / Socket: 8mm
• Fit Exhaust Studs: M6 / Nuts: M6 / Socket: 8mm
• Fit Rocker Arm Assembly: 64mm / Feeler Gauge: .004in / .005in / Socket: 9mm
• Fit Cylinder Studs: 168mm 176mm / Nuts: M7 / Washers: M7 / Socket: 10mm
• Fit 50mm Stud Spacing /Diagonal 70.5mm
• Fit Cylinder Head 50mm to 52mm 2V
• 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)