I have had this problem a few times where my MS 390 starts normally, and runs fine. But then I stop it, for whatever reason, and then I cannot get it restarted. Choked, 1/2 choked, not choked. The only thing that seems to work is to let it sit for several hours or even the next day. I tried it today (a day later) and it fired right up. I am assuming the plug is getting wet and I need to let it dry out. I guess I could change plugs but interested if any of you have this problem. Fortunately I have backups so I was able to keep going with one of them. I am cutting up the monster ash on my property that holds 7 and 1/2 cords and just doing a tank or two of gas each evening while it is cool.