GY6 180cc 63mm Big Bore Upgrade B Case

GY6 180cc 63mm Big Bore Upgrade B Case

SKU #: GY6-1004
GY6 180cc 63mm Big Bore Upgrade B Case that will increase the displacement of a Gy6 to 180cc!

*You will need to reuse some engine parts from your old engine. This is NOT a complete engine.
$390.00 In stock


Availability: In stock

This complete Power Pack comes with a 63mm bored out Cylinder and matching Machined out Crankcase with all of the oil seals installed. This means there is no machining required unlike all other kits on the market.


  •  63mm cylinder, piston, rings, pin, clips
  • Complete Super HP 2-valve head
  • Left and Right Engine cases.
  • 4x cylinder mounting studs
  • complete gasket set
  • bushings for right-hand and left-hand cases, and some bearings. 





Carburetor rejet will be neccessary.  Professional installation is highly recommended!



NO WARRANTY ON RACE ENGINE parts or engine bore up kits.  There is no warranty stated or implied due to the unusual stresses placed on these parts and because we have no control over how they are installed and used.  Steady Garage will not be held liable for any failure or damage caused directly or indirectly from use of these products or engine.  The installation and use of these products or engine shall be conclusive evidence that the user assumes full responsibility for any damage caused directly or indirectly by their use.


This product is legal for closed-course competition use only; for racing vehicles (a competition vehicle not used on public highways). Intended for off-road use or race purposes; may not meet regulations of pollution controlled roads or highways. Not legal for vehicles registered and use in California.