Clearly I'm missing someting. I'm shopping for a new outboard. Beside the price, I have not been able to figure out the difference between the 4hp, 5hp and 6hp Nissan 4 stroke motors. Each model has the exact same displacement (123cc), stroke (59X45mm) and gear ratio (2.15:1). I've checked other manufactures also (Tohatsu, Johnson, etc) and the 4hp-6hp have the same specs too. They also have the same prop size, gears (F-N-R), tiller controlls, weight, etc. Why would I pay more for a 6hp when the 4hp appears to be the exact same motor? Everyone I ask says, "The 6hp is bigger and more powerful than the 4 hp." But they scratch their head when I show them the specs. Anyone know why this is so? I'm sure I'll feel stupid when someone tells me what I'm missing.