QMB139 50mm Big Bore Cylinder Kit PS-151-258

  • $137.99
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Logo 50mm Big Bore Cylinder Kit for 50cc 4-stroke QMB139 engines. Upgrades to 81.3cc based on a stock stroke of 41.4mm! Includes cylinder, piston, pin, circlips, rings, head gasket and base gasket.

*You may need to modify your engine case to accommodate the larger cylinder.

  • Upgrades to 81.3cc!
  • Bore: 50mm
  • Overall Height: 70mm
  • Cylinder Sleeve Outer Diameter: 54.4mm