i have a 87' 172 sportcraft fisherman deep v with 1.6l seadrive with a ss 17p prop have also tried the 15p alum that came on it. my problem is when trimmed all the way in on take off the motor doesnt turn up almost like a stall, but if trim motor up a foot or so and then trim back down boat planes before motor gets all the way down and all is good. motor turns 5300 wot at about 38mph with wife and 2 small kids. Is my problem prop or motor height. the ventilation plat is at bottom of boat when trimmed to perpendicular with ground.
