I have a 2006 GTX 500ss . I bought it used 4500 miles.  I don't have a sled manual, sled ran great last year, what should I do this year for maintenance ?  Thanks

Thanks

with those miles, prior to the start of another season....
this is what I would do.....
 
I would remove my skid frame, disassemble completely,  removing and cleaning all shafts, verify that all grease zerks are working. inspect all wheels and bearings for damage, restriction, corrosion. replace any worn parts, inspect limiter strap, if frayed, take a blow torch and burn back the nylon,  if not the snow and ice will occumulate here. this is also the time to freshen up with a new set of slides. inspect rails for trueness, and or cracks, Maybe add some colored slides.  If your shocks are rebuildables, have these recharged,  most dealerships provide this service at minimum cost.  I do these every season.   while the skid is out take the time to inspect track and cooler.   torch the frays in the track too, including inside the windows.  repace any bent broken studs.  
Replace suspension, adjust tightness.  
Chain case lube should be replaced  @ every 1500 miles.  (cheap)
Fresh spark plugs (cheap)
Remove clutches, inspect and verify components,  you could just replace the springs with stock,  with over 4000 miles this would likely make a slight improvement.  Allot of guys will install aftermarket clutch kits,  probly best bang for your buck,  but these kits tend to wear quickly,  and parts arent readily available on the trail, like the OEM's are.  So keep it stock, and have less worries in the future.
make sure ramps, rollers are clean in the clutch housing, these will get gummed up some, and slow shift out of clutches,
any wear or any doubts,  i replace and have piece of mind.
carbs should be removed, and also taken apart, soaked in cleaner,  the jets will be the biggest culprits to your problems.
also jets are inexpensive, so replace if they dont clean up or show discoloration. check the small pin holes for debri....blow out with compressed air.
adjusting carbs, is a slightly more challenging task, might require some tools not in your box,  also want to inspect all cables, throttle, brakes, pads, etc.  Wonder when the snowmobile industry will go with a cableless throttle.....Love that feature on my harley.
Check your intake, make sure the reeds are in good shape,  they too require replacement at regular intervals.  The new fuel will cause a breakdown of the reeds, and carb boots.  so keep an eye on these areas.
INSTALL A NEW BELT, CHECK CLUTCH ALIGNMENT,  
clean our behind your primary clutch,  if thread from old belts get wound in there, it'll generate too much heat on the PTO seal, and could cause you to lose a seal/motor.   have seen this in the past.
skis, carbides, alignment, and dont forget to grease bell crank.
put a good coat of wax on her, and wait for snow.....