686 Pro Series Big Bore Kit
+2mm big bore kit, includes PRO Series JE Pistons complete piston kit and a Cometic top-end gasket kit. This kit is a nice ‘wake-up’ call for your 660 Rhino, Raptor or Grizzly. Available in 3 different compression ratios. This kit requires your stock cylinder to be bored and honed – if you’d like us to do that work, just contact us.