Cylinder Works Big Bore Cylinder Kit (270cc / 81.00mm) 51006-K01 — KTM / Husqvarna / Gas Gas 250 2015-2022

Cylinder Works Big Bore Cylinder Kit (270cc / 81.00mm) 51006-K01 — KTM / Husqvarna / Gas Gas 250 2015-2022

Product Description

Unlock massive bottom-end torque and overall horsepower for your 250F with the Cylinder Works Big Bore Cylinder Kit. Designed to transform your 250 into a true 270cc powerhouse, this bolt-on kit gives riders the tractor-like pulling power needed to rip out of deep loam corners, clear tight jump sections out of the inside rut, and pull strong up steep inclines. Built in the USA, this kit maintains an exact OEM external appearance while hiding serious displacement increases on the inside.

The engineering behind this 81.00mm overbore (+3.00mm) relies on a precision-honed nickel silicon carbide cylinder sleeve, providing high-efficiency heat dissipation and strict tolerances for maximum ring seal. To complete the engine package, Cylinder Works pairs their cylinder with a forged Vertex piston running a 14.4:1 compression ratio, ensuring quiet operation, long-lasting reliability, and a direct bolt-on installation that requires absolutely no case machining.

Top Features: Cylinder Works Big Bore Kit

• Increases engine displacement to a true 270cc (+3.00mm bore) for noticeable gains in bottom-to-midrange torque.
• Features a nickel silicon carbide cylinder sleeve for minimal friction, rapid heat transfer, and extended service life.
• Direct bolt-on installation requires no engine case machining or internal block modification.
• Complete kit includes the big bore cylinder, 14.4:1 forged Vertex piston, rings, wrist pin, clips, and top-end gasket set.

Please review the detailed compatibility data below to ensure an exact fitment match for your motorcycle before finalizing your purchase.

Fitment List

Year Range	Vehicle Brand	Vehicle Model & Sub-Model
2021-2022	Gas Gas	EX 250F
2021-2022	Gas Gas	MC 250F
2016-2022	Husqvarna	FC 250
2016-2022	KTM	250 SX-F
2016-2022	KTM	250 XC-F
2017	KTM	250 SX-F FE
2015-2016	KTM	250 SX-F Factory Edition

Frequently Asked Questions

Q: Does this 270cc kit require me to modify my engine cases?

A: No. The Cylinder Works big bore kit is engineered as a direct bolt-on replacement that drops right onto your stock center cases without any machining required.

Q: Do I need to remap my ECU after installing this kit?

A: Yes. Because you are increasing displacement by 20cc and adding a higher-compression piston, you must adjust your fuel mapping (via an aftermarket ECU like GET or a piggyback tuner) to prevent the bike from running lean.

Expert Pro-Tip:

When installing any top-end kit, ring end gap is critical—even on matched, boxed sets like this one. Always take the extra 10 minutes to verify the ring end gaps inside the cylinder before dropping it over the piston. Additionally, with the increased 14.4:1 compression ratio, you must run high-octane race fuel or a highly reliable pump gas mixed with octane booster to prevent engine detonation under heavy loads.

Recommended Pairings:

• KTM 250 SX-F Performance Parts & Upgrades
• Husqvarna FC 250 Performance Parts
• Gas Gas MC 250F Performance Parts

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