This Athena 300cc Big Bore Cylinder Kit is engineered for KTM, Husqvarna, and GasGas 250cc four-stroke models from 2019 to 2023. Designed to increase displacement from 250cc to 300cc, it includes a complete cylinder assembly with piston, gasket set, and the GET Boost electronic module for optimized engine performance without requiring ECU reprogramming.

Features

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  Increases displacement to 300cc for enhanced power and torque

  
  


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  Includes aluminum cylinder with 85 mm steel liner

  
  


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  High-performance forged piston with DLC-coated wrist pin and circlips

  
  


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  Complete gasket set with MLS head gasket

  
  


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  GET Boost electronic module with preloaded 300cc fuel map

  
  


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  Plug-and-play installation with no ECU reflash required

  
  


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  Developed for motocross and enduro applications

  
  

Specifications

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  Manufacturer: Athena

  
  


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  Part Number: P400270100025

  
  


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  Bore Size: 85 mm

  
  


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  Displacement: 300 cc

  
  


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  Cylinder Material: High-silicon aluminum alloy with co-fused steel liner

  
  


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  Piston: Forged aluminum with molybdenum disulfide coating

  
  


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  Wrist Pin: Aerospace-grade steel, DLC-coated

  
  


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  Electronics: GET Boost module with pre-installed map

  
  


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  Gasket Type: Multi-Layer Steel (MLS) head gasket

  
  

Vehicle Fitments

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  GasGas EX F 250 cc 2021–2023

  
  


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  GasGas MC F 250 cc 2021–2023

  
  


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  Husqvarna FC 250 cc 2019–2022

  
  


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  KTM SX-F 250 cc 2019–2022

  
  


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  KTM XC-F 250 cc 2019–2022