have a 38 fountain with dart twin 540's 650hp bravo 1's. they start losing water pressure and temps go up at 70 mph, faster I go the worse it gets. I have been told the drives are set so far up they start sucking air at high speeds. I have side pickups and have heard that someone makes pickup cups that fit over the side water intakes that force more water at higher speeds, anyone heard of this problem and solved it.

One way to cure it is to block off the top one or two holes on each side. A 5/16" ss set screw will fit and block them off. Cured the problem on my friends boat and I did it before I had the problem. We both have the same boat and setup, but my drive is 1" higher than his. I blocked off the top two holes.

I ported mine so they scoop the water, I haven't had it above 85 yet, but it works well.

What Mr. Gadgets said!