Ok, quick one for you all. I have a 029 that for the first tank of gas will run great. After that I let the saw cool for about half an hour, half of the time I will start it up and it seems really boggy, it will run for a min then things will be fine. Sometimes it will run like a champ from the get go. Other times (again about half) I will finish a cut and let off of the gas and it will die. I can then start it no problem and then it might be boggy again for a min, once I get it up to full speed it will run fine again. One thing I noticed is that if I open the gas tank I hear a sound of air moving. I was thinking that maybe the gas cap is sealing the tank and not letting air in. I am making an asumption that it is a partial vented cap, lets air in and keeps gas from getting out, or am I wrong on this? I was thinking maybe when the saw warms up a little it only works part of the time. But like I said sometimes it will run like a champ and I will not have a problem with it. The spark plug seems clean and a dark brown, so I don't think the plug is fouling up. any help would be apricated.