posted 04-04-2004 02:19 PM ET (US)
BW recommends that they AV plate be 0-3/4" higher than the bottom of the boat (hull). Often/usually you will be able to mount it higher. Typically this yields a better ride, better performance. Each hole that you raise the motor removes 3/4" of the lower unit from being in the water - this is considerable drag.Factors such as seaway, prop selection, loading and driving style can all affect the performance at a particular vertical height setting.
Basically, the advice that I have collected, followed and now promote is to raise the motor as high as you can such that you still maintain a cooling water stream and you do not get prop blowout.
Ride harshness, porpoising and top end speed are all factors that are improved (typically) by raising the engine on the transom.
When I repowered last year, the dealer mounted the motor all the way down. The degradation in the ride and performance was scary. I was all but ready to take the whole thing back when I started working on the tuning and especially vertical adjustment.
What you should do is to plan on about 2 hours with the trailer boat at the ramp to move this around and evaluate how it works for you (its easy to do this at the ramp with a few tools). Once you dial it in, you will be - I think - pleasantly surprised at the improvement in performance.
J.