Those carbs are not worth trying to tune or fix. Generally the jets get clogged up. Just get a new chicom one on Ebay. You can replace it with a tuneable 170/180 carb, but you will have to drill holes in the side to tune it. No throttle rod, boot or fitting issues when I replaced the carbs on the series of 180 saws that I had with tuneable carbs. I just has issues with access to the H and L screws. A drill fixed that easy tho in 10 seconds. O/w you can get a new fixed jet carb replacement and swap it in w/o any other changes. Either way, they are less than $10 shipped to your door.
Stihl homeowner saws are designed to run about 1000 hours, BTW. I bought seven 180c saws that a contractor ran until they stopped (for whatever reason) and he tossed them aside and bought new ones. When he had a pile of 7 he posted them on CL and I bought them all (power heads only) for dirt. I cleaned them all up and put in new air filters and NGK (BPMR7A) plugs. I got new GB bars and chains from LCS (now gone). 2 needed new carbs. One needed a new $8 coil (wire half sheared). 3 ran just fine. *shrug* They were all listed as low compression, but they must have used a car compression tool wrong to test them. The lowest was 150#. As far as I know, they are all still in service. My nephew has one, my brother another one. I still have a tuneable carb one. And I have a carcas of one that I canabalized (with coil, muffler, good engine and housing). They run good for what they are. A smaller limbing/homeowner saw.
So... you can call them cheap crap. Or you can easily fix and run them. Your choice.
