One of the most important areas of a motorcycle to check after winter is the fuel system. The gas still remaining in your tank can change its chemical makeup over time with parts of the mixture evaporating, turning what was once fuel for your machine into a brown muck, like the varnish sold in paint and hardware stores. If not remedied, this varnish can clog the jets inside a carburetor and lead to poor performance, difficulty starting or not starting at all.
Experts recommend that you clean the carburetor and pour out any remaining gas. Use a liquid carburetor cleaner to clear out any varnish residue, or unscrew the jets for an even deeper cleaning. Of course, adding fuel stabilizer and running the engine for a few minutes before storing the bike for winter will help prevent this issue.
Condensation can also form inside a gas tank during the winter, especially if the fuel level is low. In that instance, it’s a good idea to drain the tank and fill it with fresh gas.
While motorcycles can vary in a number of ways, such as in engine size and age, most variations in maintenance are related to the type of electrical or mechanical features of the machine. “An electronic ignition is virtually maintenance free,” terHorst says, “while older motorcycles with electrical systems [points, condensers] will need to be checked.”
Another area of the motorcycle that can vary is the drive type. “Bikes with chain drive require more maintenance than machines with belt or shaft drive,” terHorst says. Chains should be oiled before running, and you should check for proper tension of belts or chains. He adds that, in general, “machines stored indoors will require less maintenance than those exposed to the elements.”
After a motorcycle has sat idly for several months in the cold, there’s a chance the battery may have died. Check the individual battery cells and add distilled water if needed, and then charge the battery with an external charger. A battery hydrometer will tell you when it’s ready for use.