So how does a 2 stroke work? First it is necessary to become familiar with the major component parts:
- Cylinder head (A)
- Cylinder (B)
- Ports (D = inlet, H = exhaust)
- Piston (C)
- Connecting rod (E)
- Crankshaft (F)
- Crank cases (G)
Starting at the top, the cylinder head is dome shaped to create a space for the combustion of gases (gasoline and air mixed). Screwed into the cylinder head is a spark plug. Most 2 strokes utilize a single, centrally located plug. However, many different designs have been tried, including twin plug heads.
The cylinder head is bolted to the cylinder (typically with 4 bolts). The cylinder contains various ports: inlet, exhaust and transfer (more about those later).
Supporting the cylinder and cylinder head are the crank cases-so called as they also carry the crankshaft. 2 stroke crankcases are split vertically on most designs; however the Japanese manufacturers preferred horizontal splitting cases on all of their engines with more than one cylinder. This horizontal splitting of the cases made assembly and disassembly much easier.