How Do You Adjust The High And Low On A Chainsaw?

What does the L and H mean on a chainsaw?

They are typically labeled L (low speed jet), H (high speed jet), and I (idler jet)..

How do you adjust H and L screws on a carburetor?

If the carburetor is too far out of adjustment to run, or has been disassembled, start with turning the L and H all the way in and then open 2 turns on each needle. Then turn the TAS screw or idle speed adjustment in all the way.

How do you adjust a Stihl carburetor?

How to Adjust the Carburetor on a Stihl Weed EaterTurn the high-speed screw, marked ‘H’ counterclockwise until it stops.Tighten the ‘L’ screw all the way, then turn it one turn counterclockwise to open it.Start up the engine and allow it to warm up. The cutting tool will rotate. … Press the trigger of the machine to rev the engine.

How do I know if my carburetor is rich or lean?

If the mixture screw is more than 2 1/2 turns out turns then the Idle jet is too lean (too Small). When the mixture screw is less than 11/2 then the Idle jet is too rich (too large).

How do I know if my fuel mixture is too lean?

Your engine runs lean if your air-to-fuel mixture is too light – this means that the fuel in your ignition chamber is being igniting with too much air or too little fuel. Because your engine is running on less fuel than it should, it is running “lean.”

What is the screw on the bottom of the carburetor?

If it is the screw in front and underneath the carb throat that bolts to the intake manifold, it is a fuel screw. When you turn the screw out, it richens the mixture. When you turn it in, it leans the mixture.

How do I adjust my air fuel mixture?

Turn the screw clockwise until the engine starts to sound rough.Tightening the screw weakens the air and fuel mixture and decreases the amount of fuel flowing to the engine.Tightening the screw is also called making the fuel mixture leaner, which lowers the RPMs at which the engine idles.More items…

Why does my chainsaw dies when I give it gas?

If your chainsaw engine dies at full throttle, check the following parts: the carburetor, fuel lines, fuel filter, air filter, and muffler. … When the carb becomes clogged (which is often the result of old fuel sitting in it over a long period of time, like over the winter), it will not perform this task effectively.

What causes a chainsaw to bog down?

The Job of the Carburetor Without the right amount of air and fuel in the piston cylinder, the 2-cycle engine in a Stihl chain saw runs inefficiently and the saw loses power. … When the saw bogs down during cutting, it’s usually the high-speed screw you need to adjust.

How do you fix rich air/fuel mixture?

How to Fix Rich Air Fuel MixtureClean the mass airflow (MAF) sensor. So that it correctly detects the air coming into the engine, see to it that the MAF sensor is clean. … Check the flap of the air duct. … Check if the vacuum line is loose or has a leak. … Replace the oxygen sensor. … Replace the spark plugs.

What do the screws on a carburetor do?

Depending on the make and model of the vehicle, different carburetors may have multiple, sometimes up to four, air fuel mixture adjustment screws. These screws are responsible for controlling the amount of fuel that enters the engine, and improper adjustment will result in decreased engine performance.