The information provided above with respect to the sprockets is 100% incorrect. A smaller front sprocket will result in better accelleration and lower top speed. A larger front sprocket (more teeth) will give less accelleration and higer top speed. A good way to express these numbers are in terms of a front/rear ratio. A hypothetical example would be if both front and rear had the same number of teeth. This would be a 1:1 ratio. Another hypothetical situation would be the front has half as many teeth as the back. This would be a 0.5:1, or 1:2 ratio. This would give rapid accelleration, but would be limited on top speed due to the ratio. Third possibility would be twice as many on front as back. This would be 2:1 ratio. In this configuration, the rear wheel will turn twice for every engine rotation.
DISCLAIMER- these numbers are hypothetical only, and do not represent actual ratios for use on mopeds, but they are used to show effects of sprocket sizes.