I recently purchased a 2008 teryx used. It feels like it is taking longer to pick up speed and struggles to reach 48 to 49 miles per hour. It also has a occasional miss when at idle and when running low rpms. It pops through the exhast on decceleration. The belt makes a noise like it slips on hard acceleration but only for a second. The bike is stock accept for 26X11X12 tires on itp wheels. I have adjusted the valves the carb seems to be clean the only thing i havent done is change the fuel filter. I have two different cdi boxes a dynatek and pro con but neither one makes a lot of difference max speed is around 52 with them. I am open for any ideas as to what it may be.