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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 H and La mean on a Stihl chainsaw?
Adjusting the L screw clockwise can cause the chain to engage while the saw is idling. Adjusting the H screw clockwise increases the maximum speed of the engine and can cause damage to your saw’s engine if its operating capacity is exceeded.
What do the H and L screws do on a carburetor?
This adjustment controls the fuel flow to the low speed or idle circuit. 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.
What does the La mean on a Stihl chainsaw?
One marked “H”, for high speed, one marked “L”, for low speed and one marked “LA”, which is your low speed air adjustment for idle.
Why does my chainsaw dies when I give it gas?
Because your chainsaw will idle, but dies when it is revved up to full power, it means that the filter is only partially clogged; it will allow enough fuel to the engine to run on idle, but not enough to sustain full throttle. If the filter becomes clogged, not enough fuel will reach the engine for it to run properly.
What do the high and low screws do on a chainsaw?
Most Pro Saw Engines Have Three Carburetor Adjusting Screws: If this adjustment is set too high, the high idle speed will cause the centrifugal clutch to engage and the chain will run. Low Speed Fuel Adjustment – This is the adjustment that controls the proportion of fuel in the air/fuel mixture at idle speed.
What is the T adjustment on chainsaw?
The T screw regulates how much fuel is sent to the carburettor while idling until the throttle is pressed. L Screw – With the chainsaw still running, take a screwdriver and turn the L screw clockwise. Keep turning it until the engine almost stops turning.
What are the 2 screws on 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.
How do I know if my carburetor needs adjusting?
The engine should rev smoothly and quickly as soon as you apply throttle. If the vehicle is displaying any sort of sluggish performance or misfires when you apply the throttle, then more adjustments are required.
What is Stihl IntelliCarb?
The IntelliCarb™ Compensating Carburetor is designed to automatically adjust the air/fuel ratio when the air filter becomes restricted or partially clogged and maintains the engine’s correct RPM. This is in contrast to typical carburetors that utilize this air from the “dirty” side of the air box.
What causes a chainsaw to surge?
If you ask an expert, the number one factor behind the chainsaw surge is the engine running lean. This may be due to an air leak or possibly a clog in the tank vent or the carburetor. Surge is caused by erratic air leakage into the engine or the fuel unable to flow to form the air-fuel mixture.
Why does my Stihl saw keep stopping?
An engine stalls when it’s getting too much or not enough fuel from the carburetor. If the saw stalls while it’s idling, adjusting the idle screw, which usually is marked LA, should help. If the saw is stalling when you pull the throttle trigger or it doesn’t reach its full power, adjust the high-speed (H) screw.
Why does my chainsaw bog down at full throttle?
If your chainsaw is bogging down when you give it throttle, this is often a sign of improper gas-to-oil ratio. If there is too much gasoline in relation to the amount of oil used, this is known as a “rich mixture” and can cause the chainsaw to run poorly.
Why does my chainsaw only runs on choke?
If your chainsaw only runs with the choke on, it is likely an issue with your carburetor. If the carburetor is plugged, the engine will be starved of fuel and will not run. However, if the engine is plugged, the choke will pull more fuel through the carburetor’s idle circuit and allow it to run.
How do you use a tachometer on a chainsaw?
Record the engine speed with the tachometer. Look up your chain saw’s maximum safe speed in the operator’s manual. If the tachometer reads more than that speed, turn the “H” screw counterclockwise until the speed falls below the maximum safe speed value.
Why will my chainsaw not start?
The chainsaw’s engine is flooded with fuel. A fuel issue is one of the most common reasons why a chainsaw won’t start. If you believe fuel has flooded the chainsaw engine, pull the starter cord several times while holding the throttle, dry and replace the spark plug, and then try starting the chainsaw again.
How do you tune up a chainsaw?
How to Tune and Maintain a Chainsaw Remove the chain brake cover. Remove the chain and bar. Wipe down the whole chainsaw. Remove the top cover. Replace the spark plug. Replace air filter. Replace fuel filter. Sharpen the chain.
Which way do you turn a fuel mixture screw?
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.
