Just about everything you need to turn your machine into a dirt-eating monster
No machining required to complete installation
Nickel silicon carbide (NSC) plated cylinders
Cast aluminum cylinder construction
4-stroke pistons are made using a double-bridged forging design
Lightweight pistons with the tightest piston-wall clearances in the industry give you a quieter running engine
Engineered for maximum performance on big-bore cylinder equipped machines
Maximum strength, durability, and power
Made in the USA
Product Note:
Specification
Details
Bore
104 mm
Compression Ratio
10.2:1
Country of Origin
USA
Displacement
625cc
Material
Aluminum
Number of Pistons Included
1 Piston
Size Over Standard
5 mm Larger than Stock
Vehicle Fitment
Fitment is guaranteed or your money back plus free return shipping.
Don’t waste time installing a product that doesn't fit. We worked hard ensuring that this product is an exact fit on the vehicles listed below.
Polaris
ACE 570 2015-2018
RZR 570 2012-2021
Ranger 570 2014-2021
Ranger Crew 570 2014-2018, 2021
Sportsman 570 2014-2021
Sportsman Touring 570 2015-2021
Sportsman Touring 570 EFI 2015
Sportsman X2 570 2015-2021
Customer Reviews
Millennium Big Bore Cylinder
By Guy C. on
Verified Purchaser
Good looking product. Haven't installed yet waiting for new head bolts.
Pretty good, not much info available.
By Eric S. on
Ordered this kit winter of 2020/2021 for my 2014 Polaris RZR S 800. Hard to tell difference it has made but it probably makes a little more power by adding 100ccs. I could not find much information or test results. The 85mm pistons are Wossner that are meant for other Polaris quads. The kit will require a fuel controller despite what anyone says. Mine would idle then when warmed up would starve and die. Installed the PC5 and it’s been reliable since. This cylinder is probably overkill for NA applications therefore I intend to turbo it soon. In the meantime nobody has PC5 maps for it, I started with a Bikeman Performance map and since then it’s added a ton of fuel via Autotuner.
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Questions & Answers
I have a 09 rzr 800 intrested in the 85 mm kit will I need a fuel programmer and what do u recommend d that's plug and plat
By Bryan
Yes, you most likely will need a fuel programmer to make up for the larger displacement. One of the plug and play options we have for that 2009 RZR 800 would be from Wiseco. You can find it by searching for Wiseco Fuel Management Controller.
Any tuning required? I have a 2015 sportsman 570 sp touring and I'm running a big gun fuel programmer and mbrp exhaust will installing the 625cc kit give me issues with my mods?
By Gcorey82
I have a 2015 sportsman 570 sp touring and I'm running a big gun fuel programmer and mbrp exhaust will installing the 625cc kit give me issues with my mods? Will I have to get the ecu tuned?
I do not believe you would have any problems with installation of that kit with your other mods. You may just want to get a different tune uploaded to your programmer to add some more fuel overall.
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