Chainsaw Repair

Looking4firewood, it is pretty tough to estimate what your saw would need to get it running again without seeing it. Sometimes damaged cylinders and pistons can be repaired sometimes not. If as you say, it will not turn over that is not a good sign. First task would be to remove the muffler and have a look at the piston as 660Magnum suggested. It is not a big deal to do this, you must remove four screws and loosen two others. You will need a 3/8 ratchet and two long reach Allen sockets (4mm & 5mm). I will post a couple pictures for you later in the day. Since you already have the spark plug out it might not be a bad idea to put a little penetrating oil in the cylinder to see if it will free up the piston. Did the person you loaned the saw to say how long he had run the saw before it stopped? Better yet, did he refill the tank just before it started smoking and stopped?