2 stroke operation. In the head, towards the top of the cylinder bore, you have the intake port. This is where incoming air and fuel is sucked in to the piston bore. Near the bottom of the bore you have an exhaust port. The piston has a longer skirt. The piston it’s self closes off/seals off these ports. As the piston moves down the bore, the intake port is exposed to the top side of the piston. At this point most of the fuel/air mixture has been burned. The piston continues moving down the bore, pulling in air/fuel mixture. At the bottom of the piston stroke, the exhaust port is exposed, allowing the contents of the bore (exhaust gasses and some raw air/fuel) to begin evacuating the bore. As the piston begins to travel back up the bore on the compression stroke, it pushes the exhaust out of the bore. Moving past the exhaust port, not stopping the exhaust process. While both ports are “open” or exposed, the pressure difference causes a Venturi, pulling In more intake air/fuel. This is called scavenging. The piston moves past the intake port, sealing off the bore. The piston continues to move to top dead center, compressing the air and fuel mixture. The fuel ignites via a spark plug, or on the case of an RC engine, via compression (like a Diesel engine). As the fuel and air burn, the flame front pushes the piston back down the bore. Intake, exhaust, compression, and power strokes happen in 2 strokes of the piston. Where as on a 4 stroke engine, each of these events happen on individual strokes. The exhaust port not being sealed after the bottom of the piston skirt moves past it is the reason there is not oil in the crank case like on your car/truck engine. The scavenging effect is also the reason why superchargers, turbo chargers and nitrous are absolutely pointless on a 2stroke engine as a power added. All the boost will go right out the tail pipe. So how do you make more power? Refer to the fuel explanation I gave earlier. The fuel it’s self is oxygen enriched. So the fuel provides the additional oxygen to support more power than just gasoline can provide.