Athena 100mm 490cc Big Bore Cylinder Kit With CP Carrillo 13.5:1 Piston! This is the best and most reliable big bore kit on the market! Fits Honda TRX450R & TRX450ER. Years 2006 2007 2008 2009 2010 2011 2012 2013 2014. 100mm Nikasil Athena Big Bore Cylinder.CP Carrillo 13.5:1 Piston Kit (Includes, Piston, Pin, Rings & Clips) (Uses Race Gas ONLY). Athena Complete Top End Gasket Set. Larger Water Jackets Keep Your Motor Cooler! This is a bolt on kit with no machining required. It will work with your stock head and valves. The item "06+ TRX450R TRX 450R 100mm 490cc 13.51 CP Athena Big Bore Top End Cylinder Kit" is in sale since Wednesday, December 18, 2019. This item is in the category "eBay Motors\Parts & Accessories\ATV, Side-by-Side & UTV Parts & Accessories\Engines & Components". The seller is "azquadparts" and is located in Gilbert, Arizona. This item can be shipped worldwide.