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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. It has to work when the engine is idling.
How does a chainsaw get fuel?
A gas-powered chain saw’s engine functions much like that of a car. Simply put, the piston that drives the gears and chain is powered by energy released by combustion. Fuel in the tank is mixed with air when it’s pulled into the carburetor where it’s then ignited by a spark from the spark plug.
How does a 2 cycle chainsaw engine 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.
How do you adjust a 2 stroke carburetor?
How to Adjust the Carburetor on a Small Two-Stroke Engine Locate the two adjustment screws on the carburetor. Turn both of the screws counterclockwise to back them out. Turn each screw clockwise two full turns. Start the engine and let it warm up for a minute or two.
What are the 3 types of carburetors?
There are three general types of carburetors depending on the direction of flow of air. Types of Carburetors. Constant Choke Carburetor: Constant Vacuum Carburetor: Multiple Venturi Carburetor:.
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.
Should there be gas in the carburetor?
Pouring gasoline into the carburetor is dangerous and should not be done unless there is no other option for starting your car. If your engine backfires during the operation, the gasoline you pour could ignite while it is in your hands.
What are the two hoses on a carburetor?
The two hoses circled in red are vent/over flow hoses. Should not have any plugs in them. They basically both route between the two carbs, hanging down. Each carb has a vacuum nipple.
What part of the carburetor controls fuel entering the carburetor?
The first valve, known as the choke, regulates air flow into the carburetor to mix with the fuel and is only used when the engine is cold. The second valve opens and closes when you depress the gas pedal and regulates how much of the combination exits the carb and goes into the engine.
Can you clean a carburetor without removing it?
Cleaning a carburetor without removing it is fine. However, it can and should never replace the wholesome cleaning exercises. This is because it does not impact the entire length and breadth of the engine as should be the case.
How do you tell if you need to replace a carburetor?
Signs that indicate your carburetor needs to be replaced include: Poor fuel economy. The vehicle idles too fast. Your car floods when you try to start it. The vehicle has a rough idle. Your car stalls at low speeds. The vehicle hesitates under load.
Why does my chainsaw start and then stop?
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.
Why is my chainsaw not getting spark?
A spark plug might be defective and needs to be replaced. If your chainsaw has a defective spark plug, it cannot create an electrical current to ignite the system. Remove the spark plug and inspect if it is dirty, cracked, eroded, or damaged. If the spark plug has one or more of these issues, replace it with a new one.
What does a spark arrestor do on a chainsaw?
The spark arrestor on your chainsaw prevents dangerous hot sparks from igniting fires while you’re working. If the arrestor is clogged or dirty, however, it will also prevent exhaust from leaving the motor, which can prevent it from running.
Why is my chainsaw hard starting?
Old fuel collects moisture, making the fuel difficult to ignite. It’s possible the engine is flooded with fuel. To clear excess fuel from the carburetor, place the choke lever in the Off position, hold the throttle trigger fully open and pull the starter rope 5 or 6 times. Try to start the chainsaw.
How do I know if my carburetor float is stuck?
One of the signs that the carburetor float is sticking is when the engine will not idle. The float is not letting enough fuel into the reservoir, allowing for a constant idle of the engine. The carburetor float is stuck in the closed position, and only a small amount of fuel is seeping into the reservoir.
What does needle clip position do?
The top needle clip position is the leanest position available. This is because the needle is sitting farther down the inside of the atomizer or emulsion tube, restricting the fuel flow for a longer period of throttle slide travel. The bottom needle clip position is the richest position available.
How do I know if my carburetor is too rich or lean?
Q: How Do You Tell if a Carburetor Is Rich or Lean? A: One way to tell for sure is by “reading” the spark plugs. If the plug tip is white, the mixture is lean. If it’s brown or black, it’s rich.
