Stihl hedge trimmer

Is the replacement carburetor new, or taken from another unit?
Does it idle?
If you let it idle for a while, does the smoking clear up or get worse?
If you squeeze the trigger very slowly, will it speed up?
Does it have a choke? If it does, how does it behave if you leave it choked a little?
What's the history of the trimmer?

And smoke would dissipate

The two black screws (not the idle adjuster) controls the fuel mixture. 
 
The screw closest to the engine itself is for LOW SPEED operation. 
The adjacent (closest to the air filter) is for HIGH SPEED operation.
 
Opening, CC, richens the mix.  I suspect yours is too lean (EPA crap).  Open the LS screw 1/4 -1/2 turn and see if it helps. 
 
Once you get it running, adjust the HS screw till you get the engine running at it's highest RPM's.  Often, one screw will affect the other so you'll have to go back and forth...
 
Lastly aftermarket Chinese knock offs, IME, do not work nearly as well as OEM units...
 
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Counter clockwise