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Taida Cylinder 50mm 81cc Big Bore Kit w/Cast Piston (139QMB)

Taida Cylinder 50mm 81cc Big Bore Kit w/Cast Piston (139QMB)
ETA 45 - 60 Days

Description: High-Quality Taida Cast-Iron Cylinder 50mm 81cc with Cast Aluminum Piston for 139QMB engines. The cylinder bore is 50mm. Taida 50mm Cylinder Big Bore Kit is suitable for all air-cooled 4-strokes 50cc engines, and most Chinese imported vehicles 50cc (scooters, quads, and buggies).

It’s also recommended to get a 50mm big valve head (Part# 1100-1239) 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 81.3cc! When used with a 44mm stroker crank, engine displacement = 86.4cc!

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).


Includes the following Cylinder, Piston + Rings, Gaskets (chain tensioner gasket, compression base gasket, steel head gasket), Wrist pin, Circlips, and Taida Sticker.

•    1x Cast-Alumin Piston: 50mm
•    5x Piston Rings: 50mm
•    1x Wrist Pin w/G-clips: 38x13x9mm
•    1x Cast-Iron Cylinder: 50mm
•    Outer Sleeve Diameter 54.45mm
•    Cylinder Height (w/o sleeve): 53mm
•    Overall Height (w/sleeve): 70.3mm
•    Made in Taiwan
•    Fit Intake Studs: M6 / Nuts: M6 Socket: 10mm
•    Fit Exhaust Studs: M6 / Nuts: M6 Socket: 10mm
•    Fit Rocker Arm Assembly: 64mm or 69mm / 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 Cylinder Head 50mm to 52mm 2V
•    Fit Crankshaft 41.4mm to 44mm
•    Fit Dowel Pin Set (
•    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:
•    1.437 Pounds | 4.463" (L) x 4.156" (W) x 2.767" (H)

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Taida Cylinder 50mm 81cc Big Bore Kit w/Cast Piston (139QMB)
  • Stock: ETA 45 - 60 Days
  • Reward Points: 3
  • Part #: GY650-01050
Sold: 2
Views: 15349
Ex Tax: $86.13
Price in reward points: 87