GY6 Big Bore Kit - 58.5mm to 62mm
Choose the Big Bore that works best for you!
Available in up to 175cc!
A big bore kit increases the amount of power your engine produces on a given stroke due to the increased displacement. Most of the power is gained in the low and mid-ranges.
This kit come complete with cylinder body, piston, rings, gaskets - everything you need!
The 58.5mm (155cc) kit is a direct bolt-on replacement for your current GY6 cylinder body, and no alterations to the engine or crankcase are necessary.
This is a perfect mod to do when replacing your stock piston or replacing your rings - you've got the engine apart already, might as well get a bit more power out of it!
The 61mm (170cc) and 62mm (175cc) kits will require machining of your crankcase to allow the cylinder sleeve to fit properly. Porting out the crankcase should only be attempted by a professional or someone with the proper tools and experience. Buggy Parts NW is not responsible for end-user damage to the crankcsse from the purchase and installation of this mod.