Husqvarna chainsaw will not idle but runs just fine
Many chain saws have two needle screws, one for the idle jet and one for the main jet.
There is a pretty good chance you have something blocking the flow for the idle.  It could be a particle of sawdust, or it could be gelled fuel which sat in the carburetor for a while.  This happens frequently with high ethanol fuel.
The good news is that by disassembling the carburetor, cleaning out any junk, and reassembling it, there is a high probability that you will get your chain saw running just fine.  The cost for the parts is typically $5 to $15.  The time it will take is 30 to 90 minutes.
Prior to high ethanol content in gasoline, this repair would be infrequent.  Now, it seems, some carburetors can clog  up after 3 months of not being used, with fuel in them.
Worst case, some people will buy a knock-off carburetor which might be $20 to $60.  However my guess is that you are savvy enough to replace gaskets and clean out the parts and pieces prior to reassembly.