Have a problem that I can't quite figure out. This is the 2nd time it's happened. Started my 305 up this afternoon as I was going to take it for a last spin before it's put away for the winter. It started up ok and I let it warm up and then had to shut it down to help my wife. Came back about 2 hrs. later and started it up and it was missing on # 3 & 7 cylinders, the same as last year and I had to replace those plugs. Pulled the plugs and they were wet with gas. Put new ones in and they worked fine. Now these excel shorty plugs have only 1,000 miles on them and except for # 3 & 7, the others have 5,000 miles on them and there OK. The plugs were black and as I said before soaked with gas. What would make these plugs go bad. One thing I do have a problem with is it's very hard to start as the carb looses gas in its bowl overnight. Really have to pump gas pedal to start it especially after sitting for a week. Any comments??