My 60hp Johnson will start fine and appear to rev up in forward and reverse when on muffs. However, when I put the boat in the lake and attempt to give it gas, it barely moves and dies if I try to accelerate. It also dies when I put it in reverse. I replaced the stator and power pack about 3 weeks ago as they were bad and had no spark. Can this be the coil packs? Any suggestions are greatly appreciated.