The top to spark plugs look different than the bottom four plugs. Let me explain. The top two plugs after 2-3 hours look like they have alot of carbon buildup and(one looks a little dry)foul out whithin 4 hours of cruising operation (I do not troll whith this motor),while the bottom four are nice and oily and the color of a brown paper bag. I took the motor to my mechanic and he checked all six carbs, reed, float level, etc. and he said that everthing looks fine. He suggested that I mix the oil a little richer 40:1 than I have been 50:1. By the way, I disconnected the oil pump and premix my own oil/gas. I also only use omc oil. I also recently had the stator replaced, but I was having the same problem before this. HELP! 
SHOULD ALL THE PLUGS LOOK THE SAME AFTER ONLY 2-4 HOURS OF OPERATION??
SHOULD ALL THE PLUGS LOOK THE SAME AFTER ONLY 2-4 HOURS OF OPERATION??