Greetings! I've been lurking here a long time and have learned a huge amount from all the knowledgeable folks here but this may be my first actual post, and first time I've really been stuck on something in a while. A friend who works in resource mgmt for a local farm asked if I could help with his Stihl 261, non-running, so he took it to the local dealer where it has sat without getting any attention for 2 months. So I offered to have a look. (And this saw is not beat, he says probably under 30 hours total time on it) I checked all the basics; clean air filter, clean muffler, new fuel filter, fresh fuel, good spark. And here is where it gets more complicated. He said he was in a hurry last time it ran and may have used fuel with no oil mix by mistake, he's not sure, may have been mix fuel or not. Though he always runs non-ethanol from the local farm store. Looking at the piston through the exhaust port it looks not bad, maybe slightly scuffed but still mostly shiny. Compression is 65 and holds. Seems like it should at least run a little bit with all that covered. So on cranking I get nothing. And then with full choke multiple pulls it is not flooding - spark plug is not wet. Seems to not be getting fuel to the cylinder. Carb settings are within normal range. So I try to pull the carb and have a look. But the carb is held on by 2 pesky little 8mm nuts down inside a plastic manifold between the air filter and carb. There must be a special Stihl tool to remove them because none of my 8mm sockets fit without a real struggle, they are just a little too large in diameter, it would take a really thin walled 8mm socket to get into there. But I finally got the carb off, it's not badly varnished at all. I cleaned it out best I could with carb cleaner, reinstalled and still no fire, and no fuel to the cylinder best I can tell after cranking with full choke multiple times to be sure. So now I need; 1) The special Stihl 8mm carb tool for those pesky nuts, 2) A new black plastic manifold for between the air filter and carb because my 8mm socket is hopelessly stuck in there now. 3) A new diaphragm for the carb, maybe? 4) Advice on what it is I am over looking, and recommendations on where to get these parts, and possibly a new top end kit if the piston looks horrible when I pull the cylinder. And I've searched through the service manuals postings here but haven't found the 261 yet, apologies if it is here and my search skills are lacking. Thanks!