1996 200hp v6 evinrude did the seafoam decarbon worked well but didnt solve rough idle problem kinda a skip thing pop through the exhaust,,port side bank 2 and 4 cylinders the plugs are black powdery like substance i clean them and try again but engine will foul them also when engine is running i remove the plug wires from them and no change in motor seems to have good spark 7/16 when held.. replaced some gaskets on the carbs doesnt seem like a reed problem no blow back...have manual did adjust the 5 turns out on the screw but no change coul da weak spark or power pack going cause the two cylinders to not ignite at the right time? what was also weird is when i took the plug wire off which shocked the hell out of me through rubber handle pliers, and touch the plug boot to the plug still in the engine i then took the plug out and it looked normal like the others why would this happen help please,,,thank you compression 100 to 95 all on all 6... before i bought the boat it was having no spark with some of the cylinders and the marina replaced a power pack
