OK, heres the question, First the stats...I run a 28' Signature Offshore boat with 3 200 hp 2.4 ltr mercs, they all have nose cones and low water pick ups, no modifications to the motors and thay all have between 150 and 200 hours on them. Now, today I went out to the lake and I noticed my center motor is running 18-19 psi at 5500 and my other 2 are right at 15 psi. 3 days ago I ran this boat the whole day and the water pressures were all the same, at 15 psi. Now the temps are all the same, nothing else has changed, except the new water pressure. At idle all 3 motors have 2/3 psi, at 2000 rpm they all have 10psi, but now this counter rotating center motor has more water pressure than the other 2. But can anyone tell me why its changed from last wednesday, and does anyone think of any problems? I'm going back to the lake tomorrow and have 3 day plans on Block Island for the 4th of July. Please give me some input.