






ATHENA
CYLINDER KIT BIG BORE 300CC; KAWASAKI 250 KX '25-'26; 85MM BOR
Out of stock · stock as of Sep 3, 2026
Shipping calculated at checkout
30-day returns on unused parts
Details
Take your Kawasaki KX250 to the absolute extreme with this massive 300cc big bore upgrade. Engineered for riders who demand maximum power and torque across the entire power band, this kit delivers a revolutionary performance boost without sacrificing the legendary lightweight handling of your machine. Featuring a massive 85mm bore and a premium forged piston, this setup provides smooth, continuous power delivery for any RPM range. To make sure you get the absolute most out of your new displacement, it includes a pre-calibrated GET Boost electronic module, allowing you to unlock maximum performance safely and easily—all without modifying your original ECU or electrical system. It’s time to dominate the track and leave the competition in the dust! Increases displacement to an aggressive 296cc Massive 85mm bore (+7mm gain) for unmatched power and torque Bolt-on installation requires no crankcase machining Racing forged piston features an anti-friction molybdenum disulfide coating for durability Aluminum alloy cylinder integrated with a durable steel liner for optimal heat transfer Plug-and-play GET Boost module optimizes tuning automatically Includes: Aluminum Alloy Cylinder with Steel Bore (85mm) Forged Piston, Rings, and DLC-Coated Aerospace-Grade Wrist Pin GET Boost Electronic Module and Auxiliary Wiring Harness Complete Top-End Gasket Set (featuring an MLS stainless steel head gasket) Bore: 296cc (+7mm) Compression Ratio: 13.5:1 Note: The cylinder head and base gaskets contained in the kit are specifically developed for Athena cylinder kits. Whenever the cylinder kit is disassembled, replace the gaskets with the specific Athena spare gasket kit. DO NOT use OE (Original Equipment) replacement gaskets.
Specs
- Vehicle
- Offroad
- Weight Lb
- 0.0
- Shipping Class
- standard


