First you need to wash the bike down. Take time to clean around the
motor. You should also put a coat of wax on it.
Then you need to add some fuel stabilizer to the tank and fill it up
with your gas/oil mix. Start the bike and run it till the stabilized
fuel has run all the way through the fuel system and all the wetness
from washing it has come off.
Turn the petcock to the OFF position encase your needle valve fails over
the winter.
Next while the bike is hot drain the transmission fluid or oil. Refill
it with a cheap brand.
Take the spark plug out and spray some fogging oil, WD40, or motor oil
into the cylinder. Turn the motor about 5 times to make sure the
cylinder walls get coated with oil, now turn the motor till the piston
is at TDC (top dead center). That will keep moisture out. Now screw the
spark plug back in.
You also might want to spray the chain down with Chain Lube.
Let some air out of the tires so that there is only about 15-20 P.S.I.
this should keep them from getting a flat spot. Put it on the center
stand and cover it with something soft.
Also I like to stick a Balloon over the intake and the end of the
exhaust pipe. Just to keep moisture out.
If you have to store it outside make sure you put it on asphalt, cement
or at-least a piece of plywood.
Say good bye to your bike.
Winter might be a good time to do some yearly maintenance like adjusting
the cables.
When it gets worm again all you will need to do is change the oil (because
the oil you stored it with might have moisture or gunk in it after
sitting all winter). This would also be a good time for a new spark plug.
Pump the tires up, turn the Petcock to ON and start it up!