Sounds like you have a McCullogh Mini-Mac--I own two of them..great little saws,if you can find any parts they need..I bought a few for 5-10 bucks at swap meets for spare parts,and found out they made a bunch of different saws that are very similar,but the parts wont always interchange..
One of them had a 1/4" pitch chain thats hard to find,and the bars are darn near impossible to find at a reasonable cost--when I broke the bar on it,I ended up cannibalizing a Homelite saw of similar size and adapted the bar on it to the Mini-Mac,and used the chain off it too--its the only other one I have seen with that size pitch chain ..
Another Mini-Mac 110 I had bought for parts for that saw has the 3/9" pitch low profile chain thats much more common,and at first I was just going to swap the clutch,chain,and bar onto the Mini-Mac ,but I tried starting the saw,and found out it ran fine after a little tweaking,so I decided to just use it--all its missing is the air filter & housing--one off the other saw is just different enough that it wont fit--so I just put a peice of fine brass screen over the carb to keep the crap out..
On yours I'd just fill the tank with 40:1 gas oil mix,and use 2 cycle oil--I have used SAE 30 in a pinch but it cruds up the spark plug and exhaust ports after awhile..ashlees 2 cycle oil is better...you may want to remove the muffler and clean any carbon out of the exhaust ports in the cylinder--make sure the piston is down all the way so you wont damage it,and hold the saw with the ports down so crud wont fall into the cylinder..I have got some good saws for free,that had clogged up exhaust ports and they ran great after cleaning them out...
What I have done on old saws is fill the carb up with diesel fuel or kerosene or WD-40 and let it sit a day or more before trying to start them up--this will soften up the rubber diaphram in the carb and increase its chances of working..you may need to use gas or wd-40 to help get it fired up at first...if your lucky and there isnt any gummed up gas or varnish in the carb,it might fire up and run,and need some adjusting of the fuel mixture screws ...
