Ever Wonder about that little bell that you see hanging under some bikes?
The Liberty Bell

Evil Road Spirits. They are the viscious little demons! Turn signals ever failed to work? Maybe your battery suddenly went dead. Chances are that "Road Spirits" have hitched a ride.
"Road Spirits" love to ride, but they can't hang in the presence of a bell. The constant ringing drives them insane, forcing them to loose their grip and fall to the ground. Ever wonder how pot holes are formed? The bell has served it's purpose.
If you pick up a bell of your own, the magic will still work. But if the bell is a gift, the power is doubled and you know that there is someone special looking out for you. When placing the bell on your bike, the closer to the ground, the better. And remember, It's not safe to pickup hitch-hikers!!

This animation is for a 4-stroke engine. ...and now you know how they all really work.