Machined from 303 stainless steel that's 15% heavier than standard steel, allowing more mass in a smaller spaceNo extra gaskets or leaking plastic spacers Yamaha -- YZ 250 -- (2014, 2009, 2012, 2004, 2015, 2008, 2010, 2013, 2007, 2005, 2011, 2003, 2006,...