Now start the chainsaw and let the engine idle for two to three minutes. When the engine idles to low or sputters, then slowly rotate the ‘I’ screw in clockwise direction until the chainsaw engine runs smoothly. This sticky fuel can clog up the carburetor and cause the chainsaw engine to stall.
If you have not then it will likely be necessary before adjusting the high speed, low speed needle valves and the idle speed screw. Generally speaking you will need to close both high and low speed needle valves by turning them both clockwise until you feel them bottoming out after cleaning and installing a carburetor repair kit. From the closed position start by opening/turning the needle valve counterclockwise 1 and 1/4 turns open.
how to adjust craftsman chainsaw carburetor Related Question:
How do you adjust a carburetor on a 42cc Craftsman chainsaw?
With the engine running turn the high speed needle clockwise until the engine runs rough. Turn the needle counter clockwise slowly until the engine runs smooth. Make this adjustment with both screws and the engine should run smoothly and at the highest fuel efficiency.
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.
Why does my chainsaw bog down when I give it gas?
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.
How do you adjust H and L screws on a carburetor?
Set the idle speed screw(not L or H) so it is just able to idle by itself. This screw will have a “stop” it rests against. Now turn the L screw out until in decreases in rpm and then back in(very slowly) until it is at peak rpm. Adjust the H screw once more as above and it should be a very serviceable 2 stroke.
What is the H and L on a carburetor?
They are typically labeled L (low speed jet), H (high speed jet), and I (idler jet).
What is the T screw on a Craftsman chainsaw?
The Craftsman 3.3 chainsaw is an older model, and yours is likely to have seen many service hours. This is a potentially dangerous condition and can be corrected by servicing the clutch. Rotate the “T” screw clockwise to increase the speed of the idle.
Why does my chainsaw not stay running?
Your chainsaw’s engine needs the right supply of air to run properly. A clogged air filter can be the reason why your chainsaw won’t start or stay running. Find your chainsaw’s air filter and remove it. If it’s clogged or too dirty, wash it or replace it.
Why does my chainsaw bog down when I pull the trigger?
The reason for that may be you’re using the saw at altitude or the carburetor adjustment has simply slipped. The saw also won’t operate well at speed if the air filter or spark arrestor or carburetor are dirty.
Why does my chainsaw spark?
The most common cause of sparks from a chainsaw is metal-on-metal grinding. Whether it’s cutting through wood that has a nail in it or a grinding of gears in the chainsaw housing, a metal-against-metal grinding is the most likely cause.
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.
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.
Why does my chainsaw idle fast?
The most probable – and easiest to fix – cause of chain rotation while the chainsaw engine idles is a poorly adjusted idle setting on the carburetor. The result is that too much fuel is delivered to the combustion chamber when the throttle is released, and the engine doesn’t really slow.
How do you reset a carburetor?
If the carburetor is new or has been rebuilt, you should set it to “factory” adjustment. You can do so by adjusting the idle mixture screws to 1.5-2 turns out, and the idle speed screw to 1-1.5 turns in. Warm the Engine Up. The engine’s running temperature directly correlates with proper air and fuel mixtures.
Why does my chainsaw rev too high?
The throttle valve (butterfly) simply cuts off the supply of combustible air/fuel and the engine stops. If this adjustment is set too high, the high idle speed will cause the centrifugal clutch to engage and the chain will run. This is a dangerous condition and should never be allowed.