FULL CYLINDER KIT 300 ATHENA - INCLUDES: PISTON, GASKET AND CYLINDER

The CRF300RX Enduro shares the engine with its 250 2021 brother, but features revised ignition and fueling mappings for a gradual and more manageable power delivery on the diversified funds typical of the enduro.
Max power is at 11,300rpm and maximum torque is at 9,500rpm. The rev limiter is at 14,300rpm, in order to let the rider use the same gear beyond max power, a very useful feature for the Enduro racer.
The improvements have been achieved already from the 2020 model, through revised shaping of the inlet/exhaust ports, piston and combustion chamber, and a new cam profile which keep the exhaust valves open for longer with more overlap with the opening of the intake valves. The internal volume of the exhaust ports goes from 12cm3 to 12.7cm3, while the piston crown’s cutaways are re-shaped, increasing volume from 21.7cm3 to 22.2cm3. And to cope with the extra heat generated by the harder-working engine the radiator volume has been increased.
Bore and stroke remains 86 x 50.9mm, with a 4.5mm cylinder offset to reduce friction. The valves are titanium; 33mm inlet and 26mm exhaust.