Engines and Components› Pistons and Piston Rings
Athena
Athena 99-24 Yamaha YZ 250 2T 66.35mm Bore 2T Forged Racing Piston
SKU: A0EF S4F06640019B
Advanced — 4+ hours
Description
Part #: S4F06640019B
Athena, leader in producing motorcycle spare parts for over 40 years, unveils its new range of 4-stroke off-road forged pistons made by reverse extrusion. Produced with cutting-edge CNC machining tools, which ensure dimensional tolerances of less than 0.01 mm, Athena pistons are made of special high-performance materials (nickel, silica, and aluminum alloys) that guarantee the same reliability of the OE piston, while at the same time providing greater resistance and excellent performance. The perfectly smooth profile ensures a regular flow and the perfect flame propagation.
MIA's Description
Fitment
Fitment Guaranteed
Don’t gamble
on fit.
Log your build in the MOTORMIA app and we’ll guarantee this part fits your exact setup — or your money back, return shipping covered.
Available on iOS & Android
Specifications
| Brand | Athena |
| Part Number | A0EF S4F06640019B |
Videos
NEW PRODUCT Athena Top End Piston Kit - 2T 4T 🆕
Top End Piston Kit: all you need in one kit! 🔥
What's New - Athena new off-road Piston line
1999-2019 Yamaha YZ250 295cc M-Spec Big Bore Kit
The NEW Athena piston for KTM SX-F 350 cc dirt bikes 💥
Namura Top End Install | Yz125 Runs Again??!!
Unleash EXTREME power: Athena’s Big Bore Kit for Kawasaki KX 250
Athena #PartsofSuccess: Pistons!
Time for overhaul your dirt bike? Athena Top End Piston Kit 🔧
Custom Wiseco Yz285 Engine REBUILD Final TOUCHES To The Engine
Installing 304cc Athena Big Bore Kit With GET Boost On My 2025 Yamaha YZ250FX
Yamaha YZ F 450 cc 2020-22 - the NEW Athena cylinder kits ⬆️
🔥 ATHENA NEW EXTREME Big Bore Cylinder Kits for 250cc dirt bikes 🔥
Part 1: Installing Athena 290 Big Bore Kit- Yamaha WR/ YZ 250
Buy with Confidence
Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.
View Full Return Policy