(taken from the BCM Website)
Preparing the motorcycle:
1. Fill the gas tank and put "stabilizer" into the gas as directed on the product label.
2. If your bike is liquid cooled, be sure that your anti-freeze is rated for the lowest expected temperature in your climate. You never know if your power may go out. If there is any question, drain your radiator. Always drain race bike radiators as water-wetter solutions freeze at only 30 degrees.
3. Change the oil and filter IF it has been more than 200 miles since the last oil change. Note that you will NOT have to change it again in the spring if you change it before storage!
4. On carburated bikes, shut off the fuel valve. Drain the carbs by loosening the bolt or screw which is located on the bottom (or side) of each float bowl. Tighten the bolt (or screw) again.
5. It is a good idea to clean your bike. DO NOT use Armorall on the tires. If you want to coat the tire-wall, use Pledge. (Store sheepskin seat cover inside.)
6. Spray all chrome and metal with WD-40. DO NOT spray tires or brakes!! Take special care to completely coat all engineered components, exhaust system and fork tubes and sliders.
7. It is a good idea to "fog" your engine, especially if your storage area is likely to be somewhat damp. Fogging oils your cylinders are usually found at snowmobile and marine stores. Note: Do not run your motor after fogging until ready to ride again. Fogging is not just a winter storage procedure - fog your motor anytime it'll be unused for 2 months or more.
a. Two-valve method: Remove the spark plugs and spray the oil into the chamber. Turn the engine over a few times with the starter button (or kick-starter). Finally, replace the spark plugs.
b. Four-valve method: On late-model bikes, the easiest method is through the emission hoses which feed the side of the intake manifolds. While the engine is idling, break into the tee and spray fogging oil into both hoses until the engine stalls. Replace the hoses. On earlier 4-valve bikes, lift the fuel tank and remove the airbox lid. While the engine is idling, spray the fogging oil directly into the bell mouths until the engine stalls. Replace tank.
8. Remove the battery and store it in a cool, dry place. CHARGE the battery during storage with the appropriate battery charger once per month for 3 to 10 hours OR use a "battery tender" which is self-monitoring. The appropriate charger is one rated for 1/10 of the amp/hr rating of the battery. EG: YB14L-A2 is 14 amp/hr...use 1.4; YB12A-A is 12 amp/hr...use 1.2.
9. Put the motorcycle on its center stand or on a service stand rather than on the side stand.
10. Mice and other rodents like motorcycles! To help deter these critters, we suggest you put duct tape over the end of the mufflers and over the intake snorkels on the airbox. Several owners also like to use mothballs under the dust covers.