Here is the big bore kit proposed by ATHENA to increase the displacement of your motocross / enduro KTM SX-F and XC-F from 2011 to 2015 / HUSQVARNA FC from 2014 to 2015 in 4 stroke 350cc. This kit in Ø90mm against Ø88mm of origin thus allows to pass your motorcycle of 350cc has 366cc real! A gain of torque and performance will be immediately felt. It allows a gain of 2 HP and 2 NM on average which is huge on this vehicle. Enough to have fun on the tracks or in the forest. ATHENA has moreover well planned things because this top engine is sold complete. It includes the cylinder, piston, ring as well as all the gaskets you need for a quality and tight reassembly. The advantage of taking this engine is that it is designed to be mounted on the original connecting rod with the original cylinder head and camshaft. So you have no modification to do or adjustment! Here attached the power curve so you can see by yourself the difference between the original and the big bore. You will also find a detailed list of vehicles on which this cylinder can be mounted.