Hi. I have a stihl fs110 that my brother gave me cause he couldnt get it running. He changed the carb and the coil but it still wouldnt run so he gave up. When I got it I checked the valves and the exhaust was carboned up and leaking. Also I noticed the crank seals were leaking. I fixed all that and it still wont start. It pops and smokes like it wants to start but thats it. I put a heat gun on it for 10 min. and the **** thing started second pull. It ran like a new one and I did my whole yard with no problem. I tried starting it later after it cooled off completely and it will not start again. The only thing I can think of is the rings worn maybe. I looked at the gap when I had it down and it looked good but I didn't have a feeler gauge to check. I have a compression gauge but I dont have the right adaptor to check it. Im not trying to save money by fixing it myself, I just like a challenge I guess. Does anyone think the rings would cause this problem? If not rings what else could I check?