Born at the end of 1994 to celebrate Aprilia's victories in the 250cc category of MotoGP, the Aprilia RS 250 is a real milestone in the history of two-stroke sports motorcycles. It all started in 1987 when an Aprilia ridden by Loris Reggiani won the San Marino Grand Prix and culminated in absolute domination between 1994 and 1996 when Max Biaggi won three consecutive world titles.
Today, this full-fledged racing replica, capable of producing over 280 hp/litre, remains the most powerful 250 cc 2-stroke road bike ever produced!
The long experience gained in the world of racing has allowed the Athena R&D department to create a solution that fills a gap in the market: a standard bore cylinder replacement kit for the original Aprilia-Suzuki, which can be installed without any modification, fully conforms to the original specifications and comes with all required components.
Athena's engineering and design department manages the entire cylinder kit development and approval process. The team designs the kit elements together, then quality control technicians test them and validate the parts before their direct use by the pilots. The result is a combination of engine components that ensure optimal synergy between parts in accordance with our high standards of maximum performance, reliability and durability.
THE CYLINDER
The cylinder is manufactured from a high-silicon aluminum alloy machined using innovative technology and state-of-the-art computer numerically controlled (CNC) machine tools to ensure tight manufacturing tolerances and maximum precision.
The cylinder comes ready to install with no modifications to the crankcase required and includes the oil tank mixer fitting and brass bushing for the exhaust valve shaft, all pre-assembled. The latter features a threaded valve seat instead of the conventional press-fit type, greatly simplifying future disassembly and reassembly operations.
Athena technicians also redesigned the coolant hose because the original sleeve installed on Aprilia-Suzuki cylinders is susceptible to corrosion. They created a separate brass sleeve that can be screwed directly into the cylinder, simplifying maintenance of this essential element for proper engine operation.
The cylinder head stud seats have also been redesigned and, unlike the original, they are no longer in communication with the cylinder water passages to ensure optimal contact pressure and maximum sealing in all conditions.
The inside of the cylinder wall is coated with Motor-Niksil to ensure smoother piston sliding, less friction and reduced piston ring wear, for long-lasting, consistent performance. Motor-Niksil treatment provides additional hardness and superior strength inside the cylinder, limits wear and helps maintain nominal bore size over time.
In addition, the internal diameter of the CNC machined exhaust crosspiece eliminates the risk of excessive expansion that could damage the piston, guaranteeing optimal reliability and durability over time.
PISTON KIT
The Athena flat head piston kit has been designed and developed specifically to maximize the high performance of this cylinder kit. We have selected a high silicon aluminum alloy to ensure a low coefficient of thermal expansion and, therefore, much tighter mating tolerances between piston and cylinder.
The piston skirt is lighter for maximum performance and the surface has been coated with molybdenum disulfide to reduce friction, dampen noise and improve piston sliding.
To ensure constant and effective lubrication of the needle cage bearing and the small end shims (spacers) in all conditions, Athena technicians designed a window, made with state-of-the-art CNC machining tools, on the intake side of the piston skirt. ; On the exhaust side, the skirt has holes for lubricating the exhaust crossmember.
The included piston rings are made in Japan from a special steel and feature a chromium nitride coating applied using a PVD process, ensuring low friction, smoother piston sliding and longer life.
The piston pin is biconical for greater strength and lightness and is made from an aeronautical steel alloy treated with nitride to guarantee maximum hardness and minimum friction.
GASKET KIT
The gasket kit, developed by Athena technicians, includes all the gaskets necessary for the installation of the cylinder kit and is fully compatible with original Aprilia-Suzuki components.
The materials and manufacturing technology used to produce these seals make them particularly resistant to oils, fuels and mixtures of water and antifreeze or corrosion inhibitors. In addition, they have superior resistance to mechanical and thermal stress and adapt well to sealing surfaces.
In particular, the head gasket and cylinder base gasket have been specifically redesigned using an innovative reinforced graphite material.
As an option we offer you a stage 1 preparation, this preparation is a modification of the channels and the exhaust port by increasing the diagrams and improving the conduit, it increases the performance of the cylinder. An improvement to the piston and skirt bottoms is also included in this modification. Allow a little extra time for this preparation!
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