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HOME » 88 Monster Big Bore Kit











Revolution Performance 88" Monster Big Bore Kit

(Fits 1986-present Sportster, XB and XR1200 style Harley Davidson motorcycles)

$1,089.95

The Revolution Performance 88" Sportster, XB and XR1200 Monster Big Bore Kit is the key component to build a devastating 88" 1986-present Sportster, XB and XR1200 style engine. The monster 88" kit comes with our state of the art all aluminum NSC plated cylinders which last longer and run cooler than the OEM cylinders. The cylinders are matched with a premium forged piston in two different compression ratios and a Cometic head and base gasket kit.

    88" Monster Big Bore Kit comes with:

  • NEW 3.8125" all aluminum Nickel Silicon Carbide (NSC) plated cylinders in your choice of finish: All Black, Black Highlighted or Natural
  • Forged 10.5:1 compression ratio flat-top piston kit (-2.8cc)
  • Cometic head and base gasket kit (.030 head gasket / .020 base gasket)
  • The 88" Monster Big Bore Kit requires additional engine modifications to install and benefit from our other products and services.


    Required Services:

  • Case bore service
  • Crank balance service
  • Recommended Services:

  • 88" Monster CNC Cylinder Head Porting Package


  • ***NOTE: Compression ratio is calculated using 62cc chamber***




For questions on our big bore kits, please contact our sales technicians directly at: 1-866-892-2109 M-F 8:30 A.M. - 5:00 P.M. CST.



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