THE HEART OF THE ENGINE
Choose how to make your engine beat
At the heart of combustion
The Athena motorcycle cylinder kit
There’s a point inside every engine where everything comes to life. It’s the combustion chamber: a tiny space where pressure rises, temperature explodes, and mechanics turn into motion. There, in the heart of heat and milliseconds, the cylinder kit does its work.
The Athena cylinder kit is the combination of cylinder, piston, and gaskets that defines and seals the combustion chamber, guides the piston’s movement, and manages heat exchange. This is where sealing, efficiency, and long-term operating stability are built. They are not just three assembled parts—they are a single system, designed to work in harmony from startup to the most demanding revs.
Athena Cylinder Kit
Components
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CYLINDER KIT -
GASKETS
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PISTON KIT
A SINGLE SYSTEM
THE SYNERGY BETWEEN COMPONENTS
Three elements, one breath. We design cylinder, piston, and gaskets as a single architecture: they fit perfectly from the first assembly, slide cleanly, and keep the engine’s voice clear from warm-up to the finish line.
100% aluminum, by choice
Aluminum
Light when you need to accelerate, solid when the load increases. It’s the material that allows us to maintain smooth motion and stable performance lap after lap. Inside the bore, we apply our nickel–silicon coating (Nikasil): a uniform, durable surface that preserves geometry over time.
WE PUT OURSELVES TO THE TEST WHERE IT COUNTS
From the test bench to the checkered flag
The cycle begins and ends at Athena: design, prototype, machining, testing. From hours on the test bench we move to the track, alongside top World Championship teams, to validate the product at its limits and bring the data back to the workshop. That’s how we turn invisible details into reliability you can feel.
This “from the bench to the checkered flag” approach allows us to refine what is often unseen but always felt: tolerances, finishes, and component consistency. It’s also why Athena is an OEM supplier for production models—the same discipline needed to win on the track is what earns us a place at the birth of a motorcycle.
THE RANGE
Standard or Big?
Standard Bore Cylinder Kit
When you need to restore efficiency without altering your bike, the Standard Bore is the reassuring choice. Same parameters as the original, straightforward installation, reliability, and controlled costs. It’s the perfect balance for those who clock miles, train consistently, or want to feel their engine clean, coherent, and true to its nature again.
Big Bore Cylinder Kit
The Big Bore increases the bore diameter and gives the engine a fullness you feel on every corner exit. It’s the upgrade for those progressing on small off-road displacements or the “weekend warrior” who wants fun without losing rideability.
THE RANGE
Two or Four?
2-Stroke (2T)
In the 2-stroke world, everything is immediate: flows breathe through ports and transfers, rhythm is essential. Here, cylinder profiles and finishes matter because every detail translates into smooth motion and pure feeling. It’s the choice for those who love the honesty of mechanical expression.
4-Stroke (4T)
The 4-stroke means precision and balance: valve-controlled intake and exhaust, linear progression, long-term stability. It’s the ideal platform for those seeking consistency, efficiency, and full yet composed power delivery—perfect for training, road, and carefree track days.
MARKETS
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OFF-ROAD -
OFFROAD
We entered quietly. Now we leave a mark.
We started from dirt when nothing was yet ours. Step by step: design, bench, track. Today, in single-cylinder off-road applications, Athena is a worldwide aftermarket benchmark.
In mud, rocks, and roots, you need a cylinder kit that won’t give up: that synergy between cylinder, piston, and gaskets keeps the engine “present” when traction and control matter most.
OFFROAD - Yamaha YZ 125
Standard Bore Racing Cylinder Kit
For the YZ 125, Athena offers a Standard Bore Racing cylinder kit that maintains original dimensions and compatibility while adding a more playful track character. Targeted machining on the cylinder, a high-dissipation racing head, and a lightweight single-ring piston deliver livelier throttle response when you turn up the pace.
OFFROAD_BIG BORE
EXTREME DNA
Those who live off-road know: today, it’s not enough anymore. We sought an engine that could push harder yet stay manageable—able to deliver adrenaline without betraying MX2 agility—and we found it here: Ø 85 mm (our most radical increase), no crankcase modifications, forged racing piston with double-beam structure, and aluminum alloy cylinder with co-cast steel liner.
ROAD
The golden age continues
In the 1990s, the scooter boom created a culture: lightness, personality, street style. During that surge, Athena lit the spark with performance upgrades designed to revive the soul of those machines. And while scooters became icons, on the asphalt the myth of 2-stroke sport bikes grew—cult motorcycles for agility and pure emotion.
Today, our spare parts let you restore OEM reliability with the Standard Bore or rediscover that racing spirit with the Big Bore.
ROAD_BOOSTER
Athena’s Patent
Exclusively on the market for Yamaha–Minarelli vertical engines (MBK Booster, BW’s, Aprilia SR), we rewrote the rules. Our cylinder kit introduces a special racing-inspired bolting system that stabilizes the cylinder at high temperatures and paves the way for a redesigned exhaust. The CNC-machined flat-top piston, together with an additional intake port and side boosters, frees up flow, increases useful crankcase pressure, and improves lubrication.
ROAD_YAMAHA JOG
70 cc of pure adrenaline
For horizontal Minarelli engines, we developed a 70 cc racing kit that sharpens the JOG’s character without distorting it. The special bolting system (born from the Booster project) unlocks a new map of transfers and exhaust ports, while the two-map Selettra ignition brings throttle response exactly where you want it.
STRADALE - APRILIA RS 250
The roar of the two-stroke returns
1990s—pure emotion: the RS 250 is the 2-stroke sportbike that made history. With the Athena cylinder kit, the legend lives again—original dimensions and OEM compatibility, installation without crankcase modifications, flawless sliding, and real-world reliability for road or track. It’s a bridge between past and present: the same character, ready to ride again.
ATHENA.EU
Shop now
There’s still so much to discover about our cylinder kits. Don’t waste time—visit our website and buy the product that best suits you. With Athena, it’s not just about the application—it’s about your needs!