Removing the skid frame from the sled each year and giving it a good once-over can really be a gamechanger. You're mostly going to want to pay attention to the bearings in the ski and the sliders.
WHAT YOU NEED TO KNOW:
To check the bearings, give each wheel a spin and if makes noise, replace it. When the bearing is still inside the wheel, it's amazing how smooth you will think it's running, even if the bearing is bad.
Slides have wear marks on the side of them. By checking the full length of the side, you can see if it's worn close to the mark. If you spend a second guessing whether they can make it through the season, replace them. If they wear out on a hot spring day, the track clips will wear through the slide rails of your rear suspension, making the repair bill from $40 for slides shoot up to $300 for slides and slide rails, plus time served.
Also, it's a good idea to check all the skid frame bolts for tightness. Early 2000 Arctic Cats were famous for bolts coming loose and auguring large holes in the side rails.