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Revolution Performance June Sportster Spectacular!

20% OFF dealer cost on CNC Stage 2 and Stage 3 cylinder head porting service with the purchase of ANY sportster bolt-on or monster big bore kit!


Now through the end of June, get 20% OFF dealer cost on CNC Stage 2 and Stage 3 cylinder head porting with the purchase of any bolt-on or monster big bore kit. Use promo code: 1250Tracker. Offer good through the close of business, June 30th. While supplies last, call us today at 1-866-892-2109 to reserve yours!







In 1998, Millennium Technologies was approached by famed engine builder Don Tilley, from Tilley’s Harley Davidson. Tilley was campaigning an XL power Buell in AMA Pro Thunder series against much more powerful Ducati’s and they needed an edge. Millennium created the 3 ¾ Revolution Performance Big Bore Kit and the rest is history. We took all that experience in building championship winning race components and developed this package into a powerful and reliable street application. Revolution Performance offers a full line of sportster big bore kits including our 1250cc conversion kits and our Monster 90” big bore kit capable of producing over 115 hp. All the Revolution performance big bore kits are one piece aerospace grade aluminum cylinder with our proprietary Nickel Silicon Carbide plating process. This means your cylinders will run cooler, last longer, and make way more power. Each kit comes complete with everything you need to bolt on more power. Forged Pistons,, wrist pins, locks, rings and complete gasket kit. Call today and add one of our incredible CNC Stage 2 Cylinder Head packages for 20% off dealer cost.





Available big bore kits for your sportster!

Bolt-On Big Bore Kits

1988 to 2003 XL Sportster 883 and 1200 CC Models

Retail: $1033.95 / Dealer: $723.76

  • 201-401W 1250 Bolt-On Big Bore Natural Finish
  • 201-402W 1250 Bolt-On Big Bore Black Highlight Finish
  • 201-403W 1250 Bolt-On Big Bore All Black Finish

2003 to Present XL Sportster 883 and 1200 CC Models

Retail: $1033.95 / Dealer: $723.76

  • 201-404W 1250 Bolt-On Big Bore Natural Finish
  • 201-405W 1250 Bolt-On Big Bore Black Highlight Finish
  • 201-406W 1250 Bolt-On Big Bore All Black Finish

883-1250 Conversion Kits

Retail: $1033.95 / Dealer: $723.76

  • 201-416W 883-1250 Bolt-On Big Bore All Black Finish
  • 201-414W 883-1250 Bolt-On Big Bore Black Highlight Finish
  • 201-404W 1250 Bolt-On Big Bore Natural Finish

Monster Big Bore Kits

  • 201-408W 88" Monster Big Bore Kit Natural Finish
  • 201-409W 88" Monster Big Bore Kit All Black Finish
  • 201-410W 88" Monster Big Bore Kit Black Highlight Finish
  • 201-411W 90" Monster Big Bore Kit Black Highlight Finish
  • 201-412W 90" Monster Big Bore Kit Silver Finish
  • 201-413W 90" Monster Big Bore Kit BLack Finish


Available cylinder head porting services for your sportster!

Stage 2 CNC Cylinder Head Porting

Stage 2 service includes 5-axis CNC porting, larger valves, new guides and seats, new higher lift bee-hive springs and keepers, sand rolled ports and assembled.

Retail: $884.00 Dealer: $618.80 Dealer Special with 20% OFF: $495.04

  • XL883: 1.720" intake valves, 1.480" exhaust valves, .650 max lift springs.
  • XL1200: 1.850" intake valves, 1.615" exhaust valves, .650 max lift springs.

Stage 3 CNC Cylinder Head Porting

Stage 3 service includes 5-axis CNC porting, larger valves, new guides and seats, new higher lift dual-coil springs and keepers, sand rolled ports and assembled.

Retail: $1144.00 Dealer: $800.80 Dealer Special with 20% OFF: $640.64

  • XL1200: 1.900" intake valves, 1.615" exhaust valves, .675 max lift springs.
  • Thunderstorm: 1.900" intake valves, 1.615" exhaust valves, .675 max lift springs.



  • How to properly clean all parts before installing them on your motorcycle

    When installing a big bore kit on your sportster or any motorcycle application, the cleaning process is one of the most important steps!



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Millennium Technologies Cylinder Services website link Ballistic Performance Components website link