2Bros Parts

PISTON KIT 90MM KTM EXC-F/SX-F/XC-F 350 11-15, ATHENA S4F090000050 365CC BIG BORE

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Piston kit 89.96mm bore diameter. For Athena Big Bore cylinder. Made from a special high-performance aluminum alloy with high silicon content. Features cutting-edge CNC machining for dimensional tolerances of less than 0.01 mm. Some piston skirts have a molybdenum disulfide coating applied by screen printing to reduce friction and enhance performance and durability. Rings are produced in Japan with wear-resistant coatings (PVD or chromium nitride) to increase retention and durability. Kit includes piston, pin, circlips, and piston rings. Big End Pin Diameter 18x10.5x44.5mm. Compression Ratio 13.5:1. Displacement 350cc. Number of Segments 2. Piston Pin Type Standard. Piston Type Forged.

Specifications
SKU
56-K152.90.PIS
Brand
Athena
Availability
In Stock (1)

Fitments (31)

MakeModelYear
HUSQVARNAFC 3502014
HUSQVARNAFC 3502015
HUSQVARNAFE 3502014
HUSQVARNAFE 3502015
HUSQVARNAFE 3502016
KTM350 EXC-F2012
KTM350 EXC-F2013
KTM350 EXC-F2014
KTM350 EXC-F2015
KTM350 EXC-F2016
KTM350 EXC-F SIX DAYS2013
KTM350 EXC-F SIX DAYS2014
KTM350 EXC-F SIX DAYS2015
KTM350 EXC-F SIX DAYS2016
KTM350 FREERIDE2013
KTM350 FREERIDE2014
KTM350 SX-F2011
KTM350 SX-F2012
KTM350 SX-F2013
KTM350 SX-F2014
KTM350 SX-F2015
KTM350 XC-F2011
KTM350 XC-F2012
KTM350 XC-F2013
KTM350 XC-F2014
KTM350 XC-F2015
KTM350 XCF-W2012
KTM350 XCF-W2013
KTM350 XCF-W2014
KTM350 XCF-W2015
KTM350 XCF-W2016
General Product Group
Engine
General Product Type
Pistons & Kits
General Size
90mm
Variant Id
252945
Delivery5–8 business days
14-Day ReturnsHassle-free
Easy CheckoutCard friendly
Product details

FULL DESCRIPTION

Athena Forged Racing Piston Kit - Big Bore 90mm

This Athena forged racing piston kit is designed for high-performance motorcycle engines. Manufactured using advanced reverse extrusion techniques and precision CNC machining, these pistons ensure exceptional dimensional accuracy of less than 0.01 mm. Crafted from a special high-silicon aluminum alloy, they offer a superior balance of reliability, resistance, and performance, meeting or exceeding Original Equipment (OE) standards.

The piston's smooth profile promotes efficient gas flow and optimal flame propagation. Some piston skirts feature a molybdenum disulfide coating, applied via screen printing, to further reduce friction, thereby enhancing performance and extending durability. Each piston is engineered in Italy by the Athena R&D department and undergoes rigorous testing on dynamometer benches and in real-world track conditions to validate its performance.

This kit includes a piston, pin, circlips, and piston rings. The piston rings are produced in Japan with wear-resistant coatings (PVD or chromium nitride) to improve retention and durability, ensuring a perfect fit with the cylinder liner even under low tangential load. All included components are replaceable and interchangeable for ease of maintenance.

Key Features:

  • Forged Piston Type
  • Big Bore 90mm Diameter (89.96 mm)
  • High Performance Aluminum Alloy with High Silicon Content
  • Reduced Friction with Molybdenum Disulfide Coating (on some models)
  • Precision CNC Machining for Tight Tolerances
  • Engineered and Tested for Extreme Conditions
  • Includes Piston, Pin, Circlips, and Piston Rings
  • Japanese-Made Piston Rings with Wear-Resistant Coatings
  • Compression Ratio: 13.5:1
  • Number of Segments: 2
  • Piston Pin Type: Standard
  • Net Weight: 0.35 Kg

Technical Specifications:

  • Big End Pin Diameter: 18x10,5x44,5 mm
  • Bore Diameter: 89.96 mm
  • Compression Ratio: 13.5:1
  • Displacement: 350 cc
  • Net Weight: 0.35 Kg
  • Number Of Segments: 2
  • Piston Pin Type: Standard
  • Piston Type: Forged

Note: Products designed for increased displacement and power may be intended exclusively for competitive use. Please adhere to all local regulations regarding vehicle modifications.

Before you buy

QUESTIONS? JUST ASK

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Check the fitment table on this page against your make, model and year. Not sure? Call or email us and we will check it for you before you order.

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