basically the biggest thing is clean the valves. Pull them out by taking out the horizontal screws, clean them with oven cleaner and a wire wheel.
2005 Polaris Switchback 600: SlyDog PowderHound Ski's, SLP Air Box Mod, V-Force 3 Reeds, 144" track fully studded, Powermadd Pivot Riser and 4" block, Polaris Hand guards,