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HOME » 85 Bolt-On Big Bore Kit











Revolution Performance 85" Bolt-On Big Bore Kit

(Fits 1984-1999 80" EVO style motorcycles - 4.250" stroke)

$1089.95

The Revolution Performance 85" EVO Bolt-On Big Bore Kit is the most reliable way to increase power and torque on your 1984-1999 85" EVO engine. Each 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 available in two different compression ratios and a complete Cometic gasket kit.

    85" Bolt-On Big Bore Kit comes with:

  • NEW 3.563" all aluminum Nickel Silicon Carbide (NSC) plated cylinders in your choice of finish: All Black, Black Highlight or Natural
  • Forged 10.5:1 compression ratio dome-top pistons (+16.04cc) or optional forged 9.5:1 compression ratio flat-top piston kit
  • Cometic head and base gasket kit (.030 head gasket / .018 base gasket)
  • The 85" Bolt-On Big Bore Kit requires no other engine modifications to install but can benefit from our other products and services.


    Recommended Services:

  • 85" EVO CNC Cylinder Head Porting Package - $929.95

    ***NOTE: Compression ratio is dependent on the cylinder heads combustion chamber volume***

    ***NOTE: Dyno chart represents 85" Bolt-On Big Bore Kit, T-Man .590 cams and Power Vision tune***




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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