Sitting here at my work desk, I thought about customers’ most common questions regarding their Poulan chainsaws. The most common question I have been asked lately was how to adjust the carburetor on a Poulan chainsaw.
The adjustment procedure of a Poulan chainsaw is fairly easy and straightforward. However, Poulan chainsaws require a special adjustment tool that has splined teeth to set correctly. These tools are readily available on Amazon and are always in stock. You need these tools to properly do a Poulan chainsaw carburetor adjustment. Before you begin the adjustment procedure start with fresh gasoline with the proper fuel and oil ratio. Old improperly mixed fuel can cause a chainsaw to run erratically affecting your adjustments.
The special carburetor adjustment tool for a Poulan chainsaw can be purchased HERE ON AMAZON.
The low-speed screw and high-speed screws need to be set at baseline to adjust a Poulan chainsaw carburetor. This is achieved by setting the low speed (marked L on carburetor) and high-speed (marked H on carburetor) jets open 1.5 turns from completely closed.
Once the baseline is set, adjust the low-speed screw until the chain stops turning at idle while the throttle remains responsive. Now adjust the high-speed screw to achieve maximum permissible RPMs at full throttle.
A Poulan chainsaw carburetor is much easier to adjust if you have access to a Tachometer. The operating range of most Poulan chainsaws to idle is 2800 – 3400 RPMs, and full-throttle is 12000 – 12500 RPMs.
Note: Different model Poulan chainsaws have different operating specifications in regards to idle speed and maximum allowed RPMs. Please refer to your specific Poulan chainsaw’s owners manual for your chainsaw’s specifications.
When adjusting your chainsaw, be sure not to exceed the maximum allowed speed of idle and high-speed RPMs, as doing so can permanently damage your chainsaw. If your engine idles too fast the chain will keep turning and can result in injury.
Adjusting A Poulan Chainsaw’s Carburetor
Before adjusting your Poulan chainsaw’s carburetor, you need to make sure your chainsaw has the following :
- A clean air filter
- Fresh properly mixed fuel
- A properly firing spark plug
A dirty air filter, bad fuel, or fouled spark plug will affect how your chainsaw engine runs. To get a true adjustment of the carburetor, all other options need to be in correct working order.
Now that you have the air filter clean, fresh fuel, and a good spark plug, you are ready to adjust the carburetor of your Poulan chainsaw.
Step 1. Seat the low and high speed jets closed
Using the special adjustment tool, seat both the low-speed (marked L on carburetor) and high-speed (marked H on carburetor) all the way closed. This is done by turning both jets clockwise until they stop.
Step 2. Open the low and high speed jets 1.5 turns
Using the special adjustment tool, open both the low-speed jet (marked L on carburetor) and high-speed jet (marked H on carburetor) 1.5 turns from closed.
Step 3. Start chainsaw and adjust the low-speed jet until chain halts
Using the special adjustment tool, adjust the low-speed (marked L on carburetor) to the point where the chain stops turning while the throttle remains responsive.
Step 4. Adjust the high-speed jet to achieve maximum allowed RPMs
Using the special adjustment tool, adjust the high-speed jet (marked H on carburetor) to the point where the engine archives maximum allowed RPMs as indicated in the owner’s manual. (NEVER EXCEED THE MAXIMUM ALLOWED RPMs FOR YOUR CHAINSAW; DOING SO CAN DAMAGE THE CHAINSAWS ENGINE)
Step 5. Optional – If needed, adjust the idle screw until the chain stops moving.
In some cases, it is necessary to adjust the idle speed screw, (marked T on the chainsaw cover), until the chain halts turning. If the idle is set too high the chain will continue to move by itself. If the idle is set to low the chainsaw will not idle and will die.
How do you adjust the idle speed on a chainsaw?
The idle of a chainsaw is affected by two different adjustments of the carburetor. The low-speed jet and the T-screw, (idle screw), both have an impact on the idling of the chainsaw.
When adjusting the low-speed jet of the carburetor of a Poulan chainsaw start with the low-speed jet open 1.5 turns from closed. Once the saw is running adjust the low-speed jet so that the chain stops or is as close to stopping as possible while still having a responsive throttle.
If you are able to get the chain to stop completely at idle and still have a responsive chainsaw throttle you are done.
If you are not able to get the chain to stop completely at idle by adjusting the low-speed jet you will need to adjust the T-Screw (idle screw).
Turn the T-screw counterclockwise to slow the speed of the engine until the chain stops completely.
If you turn the idle screw too far counterclockwise the chainsaw will die, so make sure you turn it just far enough for the chain to stop turning.
Congratulations! You have successfully adjusted the idle speed of your chainsaw.
What are the L and H screws on chainsaw?
The L and H adjustment screws on your chainsaw are for low-speed and high-speed carburetor adjustments. These screws directly affect carburetor function during the adjustment process and can cause an engine to run inefficiently if improperly set.
The L screw controls the air-fuel mixture of the low end of the chainsaw’s throttle response. The low end is when the trigger is first pulled.
The H screw controls the air-fuel mixture of the high end of the chainsaw’s throttle response. The high end is when the chainsaw’s engine speed is topped out.
Adjusting the Low and High screws controls the chainsaws’ throttle response, (low end), and high-end engine RPMs.
It’s tempting to turn the L and H screws to make the chainsaw be as responsive and as fast as possible. However, this should not be done. If you set your chainsaw too lean and fast it can destroy your chainsaw’s engine.
NEVER SET THE SPEED OF YOUR CHAINSAW’S ENGINE ABOVE THE MANUFACTURES SPECIFICATIONS. PLEASE REFER TO YOUR OWNER MANUAL FOR THE CORRECT RPMS.
Why does my chainsaw die when I give it gas?
A stalling chainsaw engine can be caused by a few different scenarios. However, the most common cause is an incorrectly adjusted carburetor.
If a chainsaw dies when the throttle is engaged it indicates the fuel mixture is too rich on the low end. The low-speed jet is supplying too much fuel and not enough air. The chainsaw cant combust all of the fuel and the engine will stall. In this case, the low-speed screw will need to be leaned out (turned counterclockwise).
NOTE: NEVER SET YOUR CHAINSAW’S ENGINE TO OPERATE BEYOND THAT OF THE MANUFACTURES SPECIFICATIONS. DOING SO CAN DAMAGE YOUR CHAINSAW’S ENGINE.
Another reason could be a clogged carburetor or bad fuel.
If the carburetor is clogged it will need to be cleaned.
In the case of bad fuel, the tank will need to be drained and fresh full added to the unit.
Wrapping Up
Adjusting the carburetor of a Poulan chainsaw can be done by just about anyone.
However, you will need a special adjustment tool to turn the adjustment screws. The good news is these tools are readily available online.
When adjusting the carburetor of a Poulan chainsaw the low-speed and high-speed jet screws need to be set at baseline. This is achieved by setting the low speed (marked L on carburetor) and high-speed (marked H on carburetor) jets open 1.5 turns from completely closed.
Once the baseline is set, adjust the low-speed jet until the chain stops turning at idle while the throttle remains responsive. Now adjust the high-speed jet to achieve maximum permissible RPMs at full throttle.
Never exceed the specifications of the chainsaw manufactures maximum RPMs, doing so can damage your chainsaw.
You did it! Remember to be safe and wear your long pants, safety glasses, and leather gloves for protection.
Have a great day and happy cutting!
Steven R
