I would really appreciate some advice. I have a 50 hp Blue Band, 4 cylinder. After having it repaired (electrical problem, the stator was replaced), it has been running well. However I forgot to open the fuel valve and it stopped. Since then it has been unable to idle and is not giving full power. Have taken the carb that I thought was blocked off, checked the plugs and run some Quick Silver through it, but it still runs rough. Can anybody suggest something obvious that might have been the result of not opening the fuel tank valve and collapsing the plastic tank?