If there is too much fuel mixed with the air, the engine “Runs rich” and either will not run, runs with a lot of smoke, runs poorly or, at the very least, wastes fuel. There is an adjustable plate across the tube called the throttle plate, which controls how much air can flow through the tube. One of these screws controls how much fuel flows into the venturi at full throttle.
how do chainsaw carburetors work Related Question:
How does a chain saw carb work?
The carburetor on a chain saw is pretty simple, as carbs go, but it’s not entirely uncomplicated. The job of the carb is to accurately meter extremely tiny quantities of fuel and mix it with the air entering the engine so that the engine runs properly.
Do chainsaw carbs have jets?
They are typically labeled L (low speed jet), H (high speed jet), and I (idler jet). Your saw may be labeled differently (in the photos in the Gallery below, the idler jet is labeled “S”), but you’ll have three screws that correspond to these descriptions.
How does a 2 cycle chainsaw work?
A two-stroke engine, as explained in How Two-stroke Engines Work, has no valves or cams and generates power on every rotation of the crankshaft (twice as often as a four-stroke engine). This feature of the two-stroke engine means that it can generate twice the power of a four-stroke engine of the same displacement.
What are the L and H screws on chainsaw?
The letters on the screws represent High (H), Low (L) and Idle (T). The H screw regulates the Air/Fuel mix during high RPMs, while the L Screw does the same during low RPMs.
What does the pilot jet do in a carburetor?
The pilot jet handles the mixture from idle to 15 to 20 percent throttle. Air comes in through the front of the carburetor drawing fuel up through the pilot with a vacuum that is created as the air flows through the pilot circuit.
Can you flood a 2 stroke engine?
Overpriming or a choke that has been left open too far may cause the engine to flood, resulting in an excess amount of fuel entering the combustion chamber through the choke. You can start your two-stroke engine relatively easily if it is flooded.
What does the float do in a carburetor?
A float chamber is a device for automatically regulating the supply of a liquid to a system. It is most typically found in the carburettor of an internal combustion engine, where it automatically meters the fuel supply to the engine.
Does a carburetor add horsepower?
How Does A Bigger Carb Give More Horsepower? A bigger carburetor has a bigger space that can help to increase horsepower by allowing more air and fuel to travel into the combustion chamber at once. More air and fuel in the combustion chamber means bigger combustion is generated. Thus, more horsepower.
Why are carburetors not used anymore?
Most car manufacturers stopped using carburetors in the late 1980’s because newer technology was coming out, such as the fuel injector, that proved to be more efficient. There were only a few cars that continued to have carburetors, such as the Subaru Justy, until about the early 1990’s.
How do I know if my chainsaw is 2-stroke or 4-stroke?
A 2-cycle engine has one fill port with a cap that has fuel pump and oil can icon. The cap will usually state the oil to fuel mix ratio. A 4-cycle engine has two fill ports with each cap separately identifying the fuel tank from the oil sump.
What is the mix ratio for chainsaw gas?
The general ratio for most two-stroke chain saw combustion engines is 50:1, though some manufacturers recommend 40:1. The larger number represents the amount of gasoline, while the smaller is the amount of oil needed.
Are chainsaws two-stroke engines?
These days, you’ll find two-stroke engines in all kinds of gas equipment, such as chainsaws, string trimmers, hedge trimmers and leaf blowers, largely because two-stroke engines have fewer moving parts, generate less heat and are in many ways more efficient for their size.
What are the two adjustment screws on a carburetor?
There should be two screws on the front of the carburetor, which are used to adjust the air and fuel mixture. Often these look like flat-head screws and you can use a screwdriver to turn them, adjusting the amount of fuel and air mixing in the carb.
What does a carburetor connect to?
The carburetor is a pipe above the engine cylinders with an air pipe and a fuel pipe connected to it. The air pipe brings in outside air, first through an air filter to remove dirt and other debris, and then to the carburetor. The carburetor, also known as the carb, has two valves that perfect the air to fuel ratio.
Why does my Poulan chainsaw dies when I give it gas?
The carburetor might be clogged. A clogged carburetor is often caused by leaving fuel in the chainsaw for a long period of time. Over time, some of the ingredients in the fuel may evaporate, leaving behind a thicker, stickier substance. This sticky fuel can clog up the carburetor and cause the chainsaw engine to stall.