Cylinder Italkit d.47mm 12° piston KTM 85 SX 18-25 / Gas Gas MC 21-25

Cylinder Italkit Ø47 mm piston 12° for KTM 85 SX 2018-2025 and GasGas MC 85 2021-2025, developed with two fundamental goals in mind for a competition engine: maintaining performance and improving reliability.

In these engines, one of the delicate points is the rear transfer port. Italkit has redesigned its geometry to reduce the risk of failures caused by the piston ring, a problem that can end up damaging both the piston and the Cylinder itself.

With this new configuration, the aim is to achieve a longer service life for the Cylinder without sacrificing performance, making it an especially interesting option when it is time to rebuild the top end of the engine and you want to address one of its critical weak points.

The Cylinder is made from aluminum-silicon alloy (Al-Si) and uses a Nikasil inner coating. This combination offers high wear resistance and good heat dissipation, something especially important in a 2-stroke engine that usually operates at high RPM and temperatures.

The kit includes a 1-ring piston with a 12° crown, a configuration designed for high-performance 2-stroke engines. Using a single ring reduces friction and moving mass compared to a 2-Piston rings piston, helping the engine to gain RPM more quickly and respond more immediately. The 12° machined crown is designed to work with a specific cylinder head insert of the same geometry, allowing more precise control of the Squish area and the combustion chamber. A properly adjusted Squish improves the speed and turbulence of the mixture at the moment of combustion, achieving faster combustion, better mid- and high-range response, and more efficient use of the pressure generated on the piston.

Why install this Cylinder?

• Redesigned rear transfer port to reduce the risk of failures related to the piston ring.
• Greater reliability and durability of the engine top end.
• Manufactured in aluminum-silicon for good heat dissipation.
• Nikasil coating with high wear resistance.
• Maintains a configuration designed for high performance.
• A great option for rebuilding the top end of an engine that already shows wear.

The kit includes:

• Cylinder Italkit Ø47 mm in aluminum-silicon with Nikasil coating.
• 1-ring piston with 12° domed crown.
• Top end gasket set.
• Piston pin bearing.

Cylinder head insert not included. Italkit offers different Ø47 mm cylinder head insert configurations to adapt the assembly to the type of piston and the level of tuning.

Available cylinder head inserts:

• CU.34.85.1: for domed crown piston, compatible with kit CI.34.085.G.
• CU.34.85.1A: high-compression version for domed crown piston.
• CU.34.85.2: for Italkit 4279/1 piston with 10° crown.
• CU.12.85.3: for Italkit 2984M piston with a 12° head.

Compatible models

KTM

• 85 SX 2018-2025

GASGAS

• MC 85 2021-2025