How a dirt bike kickstarter works is via a lever that is pushed down with you leg. The kick start lever is connected via a spline to a sprocket, which is engaged with another sprocket that’s connected to the engine’s crankshaft. When the kick start lever is pushed down, this turns the engine over and the engine should start. The benefit of having a kick start on a dirt bike instead of an electric start is the bike will be lighter.
A 2-stroke dirt bike engine works on two strokes or cycles of a piston. On one of the two strokes, the air-fuel mix is drawn into the combustion chamber via the transfer port from the crankcase. As the piston nears the top of the combustion chamber the spark plug ignites the air-fuel mix. This combustion creates high pressure, which forces the piston down on the second of the two strokes. As the piston rose during the first stroke, this reduced the air pressure in the crankcase. This reduced pressure draws in more air and fuel mix, in preparation for the next cycle or stroke. This process starts over again to start the first of the two strokes once more.
How to make a dirt bike street legal depends on the type of dirt bike you have and your budget. You are better off buying a dual sport version of a dirt bike in the first place, than you are spending on converting one yourself. The requirements for a street-legal dirt bike will vary from country to country and from state to state in countries like America. Most, if not all dirt bikes can be converted, but it then comes down to cost and hassle.