I got the boat a couple weeks ago. Noticed it was real sluggish last time we took it out. Rebuilt and cleaned the carbs. Drained fuel and put in new with seafoam. Changed plugs also. Did compression test all around 110. Did a spark test at idle and seemed to me that it was real spurattic. Noticed small blue/purple spark and when the motor would miss or straighten up I'd see a long orange spark?
http://youtu.be/iVMPGoE2QHo
http://youtu.be/iVMPGoE2QHo

