Yes, your saw will need adjustment after installing a new muffler to ensure it runs correctly with the increased airflow.

If your saw has a carburetor, it will need manual tuning to avoid running lean and potential engine damage.
If it’s a Stihl with M-Tronic, the system will require a reset or recalibration.
If it’s a Husqvarna with AutoTune, the saw will need AutoTune adjustment, which usually happens automatically but may require some run time.

Proper tuning ensures optimal performance, longer engine life, and safer operation.

Start the saw cold (don’t touch the throttle).
Let it idle for about 90 seconds.
Make 5 to 6 full-throttle cuts through wood (or simulate under load) to let the system recalibrate.
After a few minutes, the saw will automatically adjust fuel delivery for the new muffler.

Tip: If you notice erratic behavior, warm up the saw, then repeat the full-throttle cuts.

Start the saw and let it warm up.
Perform several full-throttle cuts under load.
After a few minutes of cutting, AutoTune will fine-tune the fuel and air mixture automatically.

Tip: Usually, no manual reset is needed—just run the saw under load.
Chainsaw Carburetor Tuning:

Locate the carburetor adjustment screws—usually labeled H (high speed), L (low speed), and T or LA (idle speed).
Start and warm up the saw.
Adjust the L screw for smooth idle and throttle response.
Adjust the H screw to reach optimal engine speed without over-revving (check your saw’s manual for max RPM).
Fine-tune the T screw so the chain doesn’t spin at idle but the engine runs smoothly.
Test under load and make small adjustments to eliminate bogging or hesitation.