Actually, all Echo Saws are preset, carb wise, at the factory..except for the 670 and 8000 models, those have to be tached and are dealer sold ONLY.
You can bring one home, dump in some mix gas, and go to work, as is. They do sometimes run a little "lean" through the first tank or 2, and that is simply the rings seating, and stuff such as that. We have yet to have one that didnt run perfectly out of the box, or needed tweaking, and this goes for saws, trimmers, blowers, hedge clippers...etc.
When first cranked, out of the box, we idle for 30 seconds, then gradually bring it up to wide open over about 30 seconds, then slowly go back to idle. Then a few quick revs to wide open. Then idle for a few seconds, then cut off. Then restart on 1 pull, no choke. Works like a charm, and they love it.
people that buy theirs from HD always come in complaining about how they went to run it new, and it would only bog..so they had to pop off the EPA limiters and richen them up...now they complain they have no rpms...
I still say ECHO shouldnt sell to box stores...some people just shouldnt be allowed to own..very well setup, their own gas powered tools