Experienced gardeners share their insights in answering this question :
These jets are pre-set from the factory .they interlock with each other.make sure the air vents on flywheel side are not blocked.You will probably have to rebuild or replace carb.

How to Identify and Fix Common Gardening Problems ?

We provide a variety of viewpoints on how to identify and fix common gardening problems. Our sources include academic articles, blog posts, and personal essays from experienced gardeners :

Fuel Filter is Clogged

When it`s clogged, this affects the flow of gasoline to the engine which then causes the engine to stall. The fuel filter will need replacing if it appears to be clogged yet if it seems clean, it may be a different problem causing the engine to cut out.

If your chainsaw engine dies at full throttle, check the following parts: the carburetor, fuel lines, fuel filter, air filter, and muffler. Our repair guide can help you identify the right part to stop your chainsaw`s engine from dying at full throttle.
1. Dull chain and or improper lubrication to the bar and chain, sharpen and or clean the bars oil holes. 2. Air filter and fuel filter for restrictions and contamination, clean or replace as needed.
Oil and Fuel Mixture Incorrect (fuel)

Adding more gasoline to your mixture should clear the smoke. However, if you notice an overheating saw, try adding more oil to your fuel mix. Failure to add any oil to the fuel mix will cause destruction of the engine.

If the engine is low on power, it will bog down when you try to accelerate. This could be caused by a number of different issues, including low compression, a bad timing belt, sucking too much air, or even a head gasket leak.
Fuel: Make sure it is fresh and correctly mixed (see `Starting Issues`). Air filter: Make sure it is clean and unclogged. Fuel cap: Make sure it`s hand-tight. Please ensure when you are attempting to use the chainsaw that the chain brake is disengaged.
There are many factors that can stop your chainsaw from running, including a bad spark plug or dirty air filter. There are simple problems: a broken fuel line, bad fuel, wrongly calibrated high-low adjustment screw. Also, more complex issues like a damaged carburettor or an engine compression problem.
The two most common reasons a chainsaw won`t idle are a blocked air filter and an idle screw out of adjustment. Other possible causes include: Dirty Air Filter.
If the carburetor is clogged, it may only work with the choke engaged, which is not a good way to be running your engine. Cleaning the carburetor and replacing some of the internal parts with a new carb kit is a great way to get your carburetor running properly again.
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. The T screw regulates how much fuel is sent to the carburettor while idling until the throttle is pressed.
STIHL recommends that you do not run your engine at wide open throttle without a load. A blower is under a load at all times, a trimmer is under a load as long as the trimmer head is in place and the line is to the correct length, while a chainsaw is under a load when the bar and chain are in a cut.

Discover Relevant Questions and Answers for Your Specific Issue

the most relevant questions and answers related to your specific issue

Chain saw starts and stays running in half choke but as soon as you put it in run it diesl
ANSWER : The machine is running too lean, start by checking the easy stuff first, pull the fuel hose out from inside the fuel tank, clean/ replace the filter on the end of the hose ( as a temperary test fill the tank with fuel and try the saw with no fuel filter on the hose, if it runs better then the filter is blocked ), follow the fuel hose up to the carb, check for any splits or cracks, pay special attention to the area where it leaves the fuel tank, and where it fits to the carb, if it is still no better, make an adjustment to the carb mixture screws, they are marked H and L there will also be a screw marked T or I this is just the tick over screw. Unscrew both H and L screws ( anti clockwise ) 1/2 turn, this will richen the mixture, if not much better unscrew the L screw a further 1/2 turn. If the saw has not improved there is a blockage in the carb, let me know what make and model of machine we are working with so we can talk about cleaning the carb.
Regards Andrew

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Will only start and run in choked position, when throttle applied chokes out. If started with out choke and throttle position in low speed will start and run for 10 sec then like it runs out of gas.
ANSWER : I have your solution guaranteed, I fixed mine yesturday remove H L screw plastic caps and on high 11 threads exposed and on the low side 8 threads exposed. removing the plastic caps allows u further adjusting these wear out or move soo just take them things off and you will be rolling

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My Poulan will start and run fine, but when i give it gas it revs up and dies every time. Ive messed with it some, and ive noticed if i close the choke right before it dies, it keeps cutting, but i have to keep my fingers on the choke which is very burdensome. Im not sure what it is!
ANSWER : Afternoon Jacob;
If you must choke it for it to run it is to lean. Have you cleaned the air filter? Might be good idea. An air leak can also cause this inspect the intake for a loose or defective connection at the engine or carburetor.
If these are good try to adjust the “H” needle valve CCW (richer) a little.
You can find a very good description of adjustment here:
Carburetor Adjustment by
CW is leaner; to lean will destroy the saw. If over tightened closed (CW) the adjustment screw faces are easily marred; marred adjustments are difficult to impossible to set properly.Clean the air filter; adjusting with a dirty filter can cause a run lean condition once cleaned and the saw run.
There are 2 wav (sound – idle & full – may not be highlighted) files that I find most helpful, I think you will too. Good Luck

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Won’t idle ,runs wide open unless you pull choke,solutions?
ANSWER : Maybe a carb overhaul can do the job.

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Carburetor tool i need to adjust my carb on my husky 455 chainsaw but it has a special adjusting screw. where can i get the adjustment tool.
ANSWER : The splined Poulan Carb Adjustment Tool, 530035560, which was readily available for less than $20.00 before 2013, has become scarce and bottom the feeders are price gouging. Check and I just received one and it is the quality item at very reasonable price, $14.00

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Have to run on half choke,just stops if i turn it off.fuel is 25 to 1. thanks alan.
ANSWER : More than likely a small passage way in the carb is clogged. You can try some carb cleaner, but you may need to disassemble the carb and clean it out. Be advised that these passageways are sometimes as fine as a human hair, and almost impossible to clear sometimes. A new carb may be required if it is worth it to you. Sorry.

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My mantis will not stay running unless the choke is full on
ANSWER : Sounds like the fuel pump diaphram in the carb. you need to either be familar with it or take it to thae shop to replace

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I have a 42 cc 18″ poulan chain saw I cant get it to idle its either all or nothing. I cant start if the chain break is on and when it starts the chain runs. It dies under stress and then is a struggle to start when its hot.
I havent had much use out of it and its always tended to die under strain
I have changed fuel, cleaned filter and arrestor and tried udjusting idle speed but if i go slow it dies. I am tempted to adjust the h l knobs but dont have anything to fit them. What does?
What help can you give?
ANSWER : If the chain runs at idle, or tries to turn when cranking the saw, then there is an issue with either the clutch drum bearing or the clutch spring has become weak, to get to both of these components you need special tools, the tool to remove the clutch is part no. 530031112, and the tool to adjust the carb screws is part no. 530035560, the L screw will adjust from idle to half throttle including acceleration, the H screw will adjust the full engine speed

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