Exhaust system matters a lot. How your ATV works partly depends on the type of exhaust system you have. 2 stroke system differs from the more common four-stroke cycle. The former has only two strokes linear movements of the piston instead of four. Despite this difference, both still perform the same four operations – intake, compression, power and exhaust.



With 2 stroke ATV Header Pipes, there could be a short-circuiting of fresh charge from intake to exhaust which increases fuel consumption and emissions of unburned hydrocarbons. To minimize the mixing of the intake and exhaust flows, the cylinder ports and piston tip are shaped and positioned. Also, back pressure is provided by a tuned pipe with an expansion chamber at just the right time to push fresh air-fuel mixture sneaking out the exhaust back in again.

By using 2 stroke ATV Header Pipes, this is how the engine works. As the piston reaches the peak of its stroke, the mixture will be ignited. And by the fast expanding gases of combustion, the piston will be forced down. Now, a hole near the cylinder connected to the exhaust pipe is opened giving way to the burned gases to escape. It also shuts the inlet port and pressurizes the crankcase, pushing some mixture from the crankcase back to the inlet tract. This causes the reed valve to close and prevent the mixture from entering the air filter.

Now, the air fuel is forced into passageways connecting the crankcase to the cylinder. The holes connected to these passages to the upper cylinder are uncovered by the descending piston and air-fuel mixture is likewise forced to the upper cylinder. Since the transfer ports are lower than the top of the exhaust port, there’s a period of time for air-fuel to come as the exhaust leaves. When the piston reaches the bottom and begins to rise again, the transfer ports are closed by the piston and the air is compacted.

Changing your 2 stroke ATV Header Pipes on your ATV can have a marked effect on the engine’s power characteristics. This is because the two stroke system makes use of pressure waves emanating from the combustion chamber effectively supercharge your cylinder. Basically, expansion chambers are built to harness sound waves created in the combustion process, to first suck the cylinder clean of spent gasses. One advantage with this pipe system is the fact that it is easy to tune.