Hello. I was playing with my setup and think I went too far. I have a 1994 Stratos 201 Pro XL, with a 2004 Mercury 200 EFI. I have 8 inches of setback, and I run a 25p Tempest+ that's just been rebuilt. Last fall, when it was cool and I was by myself, I got 65 mph at 5600 rpm. This was at 2.75 inches below pad on just the 5 1/2 inch plate. I wanted to get the RPM up a little closer to the 5750 recommended WOT so I added the extra 2 1/2 inches of setback over the winter. Yesterday, I played with the engine height some and raised it a little at a time making passes and recording speed. Each time I went up, I gained a little bit (tenths of a mph) of speed, and a few RPM. When I finally lost water pressure, I backed it down to the last setting where I still had good pressure and left it there. End result was 63.5 mph at 5600 (it was in the low 90's and I had 2 extra people on board with all their crap so I'm not surprised the numbers were a little lower than I normally get).
While testing, I noticed my speedometer wasn't working over 50 mph, but I was going by the GPS anyway. When I got home, I measured prop to pad. I used 3 different levels to verify, and measured many times to make sure because I couldn't believe I had it so high, but my prop was only 1.5 inches below pad. The speedometer likely quit working because I use the pickup on the lower unit, which at that height was out of the water. I didn't loose water pressure until I actually raised the Jack plate as far as it would go, then dropped it just a little and got it back. I run the Mercury water scoops on the lower unit, which allow you to run a little higher and maintain water pressure.
From what I've gathered, 3 inches to no lower than 2.5 inches below pad is normal on these hulls. So what gives? I kept gaining speed and rpm, although very little, each time I raised it. I know my water scoops allow me to raise the motor more than typical, but I was thinking I would loose speed if I went too far. I've backed it back down to 2 inches and I'm going to run it again tomorrow, but how high is safe? Where should I stop?
One last thing, here's a pic of the low water scoops in case anyone is scratching their heads trying to imagine what they are. Thanks!