1990 175 prescion blend, wot rpm? is 4700 low at wot

[alex3012red]

My engine's wot rpm is only 4700 rpm., is that right or is it too low. I changed plugs, fuel filter on motor,(haven't changed water seperator). cleaned carbs( set screw at 2 1/2 turns out) smokes a little at Idle. This is a new boat to me so I have no clue if my rpm's are o.k. I cruise at 4k at 30 mph.

[boats.net]

The operating range for that motor is 4500-5500. 4700 is low and would be better if run on high side of range, might try a lower pitch prop.