Winterizing a Ninja 250
Not all of us live in areas with a climate that allows for safe year-round riding. It's no fun (and it's not safe) to ride in ice and snow, and it's not very pleasant riding when the temperature is below freezing, even with warm clothing. Many motorcycle riders store their bikes over the Winter, then bring them back out in the Spring when the weather has improved.
So what do you need to do if you don't ride for 3 months? Well, the last thing you want to do is leave the bike outside without any preparation. Ideally you'd store it in a shed or garage where it's protected from the weather. But is that all? The answer is no. There are several things you can do which will make it much easier to get the scooter back on the road and running well in the Spring.
Gas doesn't like being stored for long periods of time. The gas in the carburetor can evaporate leaving deposits behind which can gum up the operation. Ideally you should drain the gas from the tank AND from the carburetor. Most carburetors have a method to drain the gas from the bowl. At the very least you can drain the tank, then run the engine until it uses up the gas in the carburetor. There may still be some gas in the float bowl though, so drain the bowl if you can.
Use the gas in your car so it doesn't go stale. If you want to store it for some reason, make sure you add a small quantity of fuel stabilizer (such as STA-BIL) to it to remove water and prevent the formation of gum and varnishes.
If the bike is going to be stored for a long time without being run (>6 months) you might also want to use fogging oil in the cylinders. You remove the spark plugs and spray the oil into the cylinders. The oil is specially designed to cling to the walls of the cylinders and protect them against corrosion.
As an alternative to draining the tank, some people suggest leaving the tank full of gas (with fuel stabilizer added) so that you don't get any rusting from condensation. If you take that route you should add stabilizer to the fuel then ride for a few miles to get the stabilized fuel to the carburetor. You still probably want to drain the gas out of the carburetor float bowl before prolonged storage.
Bring the battery indoors. Batteries don't like cold or standing without use and 3 months outdoors in freezing temperature will likely kill it. Ideally you should attach the battery to a float charger. This keeps the voltage up without putting a lot of current through the battery. A good charger (like the one shown on the left) will sense the battery charge and reduce the voltage when it's fully charged. The Battery Tender Plu is a 4 stage battery charger/maintainer that can be used on most small lead acid batteries such as those found on motorcycles. It uses micro-processor technology to charge and maintain the battery so it will be ready when you are ready to use your bike again.
Make sure the bike is properly tuned and running well before you store it. If it's hard to start and doesn't run well before you store it for a few months over the winter, it's going to be even harder to get it running again in the spring. It's better to do a tune up before you store it.
Also, do an oil change BEFORE you store the bike. Oil picks up all sorts of corrosive contamination and moisture and leaving the engine cold and sitting in old oil isn't a good idea. You could just drain the oil, but it's safer to change it in case you forget to replace it in the spring!
If you can jack up the bike so it's not putting its full weight on the tires, that's worth doing too to avoid "flat spotting". Just using the center stand might be enough. You might want to check the tire pressures over winter too and keep them properly inflated.
Clean the bike. Don't leave corrosive deposits to do their worst over the winter. Clean off all the dirt and lubricate things like the brake linkages and throttle cable.
Cover the bike with some sort of breathable cover. You don't want to cover it with plastic which allows condensation. Indoors you can use any sort of fabric. Outdoors you'd want to get a cover designed for motorcycles which allows condensation to evaporate.
Make sure that you have enough anti-freeze in the cooling system to prevent freezing on the coldest days. Plug the exhaust pipes. Mice like to look for places to live in the winter too!
It's not a good idea to just store the bike and simply run the engine for short periods of time over the winter because if you don't get everything hot enough, this may add moisture to the engine, exhaust etc., which can then cause corrosion. What I do is to take the bike out for a 10 mile ride if and when there's a day over 40°F with no snow or ice on the road. If course if you live in Alaska, such days are few and far between, but in New England there are usually such days throughout the winter.