Wash it off
Fill fuel to eliminate condensation and stabilize
Remove belt
Change oil and filter (Four stroke)
Change spark plugs
Run sea foam through it
Run Fogging oil through it
Block off exhaust, airbox and other openings from critters.
Grease any grease points and lubricate moving parts
Change chain oil and check chain adjustment
Disconnect battery and trickle charge over summer - clean battery connections
Lift track off ground / block up
Lubricate throttle linkage and brake lever.
Oil coat track clips, rear skid and front suspension to prevent rusting
Remove any touring bags that critters can get into.
Inspect machine and make a parts list for the fall.