There are a few steps involved in tuning a chainsaw, and they have to be done in the right sequence.
The three adjustment screws on your carby are: L - low speed fuel/air mixture; H - high speed mixture; T - throttle opening at idle.
As aussietrev says, first check for problems around the carby itself.
Then, follow the procedure detailed in this online how-to - it's really good, and includes a couple of audio clips.
https://store.chainsawr.com/blogs/t...ment-and-tuning-of-a-chainsaw-carburetor
