Airsal 50mm Big Bore Cylinder Kit for QMB139 50cc

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$95.99
SKU: 158-3
Restock: Late December

This item is IN STOCK

Current Stock: 5

Airsal 50mm Big Bore Cylinder Kit for Kymco Agility 50 and QMB139 50cc Engines. Kit includes cylinder, piston, rings, piston pin, cir clips, and gaskets. Aluminum cylinder construction for better heat dissipation.

When used in conjunction with a stock crankshaft the total displacement comes out to 81.3cc! Your stock head can be reused. High compression piston included! .5mm taller than most standard 50mm big bore kits.


*You may need to modify your engine case to accommodate the larger cylinder. Not compatible with Sym Symply 2. On some Chinese QMB139 engines, the cam holes may need to be enlarged.

Please see our Warranty & Returns Policy.


  • Upgrades to 81.3cc
  • Cylinder Bore: 50mm
  • Cylinder Sleeve Outer Diameter: 54mm
  • Compression Height of Piston: 20mm
  • Cam Hole Diameter: 6.5mm
Kymco, QMB139 50cc/49cc , SYM, Various unlisted makes/models

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