72cc GY6 QMB139 Four Stroke Big Bore Kit — 47mm. Emission head and performance camshaft included. Increase in horsepower and torque. Each kit includes: Milled Emissions Head with 18mm diameter intake and 16mm diameter exhaust valves and high performance springs. Valve stems are 69mm long. Cylinder, piston, piston rings, piston pin, clips and top end gaskets. Camshaft IS included(most BB kits do not include a performance cam). In the picture the cylinder and head are shown from both the top and bottom for clarity, only one set is included with this kit. With a big bore kit like this you should upgrade the main jet to a size 85 or 90 to keep the engine from running too lean. Please NOTE: If you open the gaskets, if you install the rings, if the kit is installed in anyway you CANNOT return it. Please be sure of what you’re buying. Any returned kits will be subject to a 20% restocking charge.

Product Features

  • Fits many Chinese Scooters.
  • Free Shipping To Continental US
  • Please note, any product that is returned will be refunded minus the original shipping costs.(i.e. The cost to ship the order to you)
  • Please Note: many photos are stock images and although no functionality will change, the part you receive might vary in color or aesthetic appearance.

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