overheating at 3000 rpms

[perhaps125]

I have a 33' avanti center console with twin 250 yamaha two strokes. The port motor loses water pressure at 3000 rpms. Yamaha replaced the entire head and put a new water pump in. Still loses water pressure at 3000. Yamaha switched the motors and the problem followed the side of the boat and not the motor. I had the hull surveyed and nothing is wrong. The only suggestion I have had is to check the exhaust housing adapter plate. I can't find it on the schemetic in the manual, and I need suggestions. I have owned the boat for twenty years and never had a problem. Will low water pickups help?

[TAXXIVADER]

when they swapped em over , did they swap just the powerheads or complete engines.?

[flabum1017]

Have you added anything to that side of the boat like a transducer or water pickup?

[perhaps125]

Both engines, and then swaped the lower units. Actually tried it both ways.

[perhaps125]

I have not added anything to that side of the boat. The only thing I had done was to have the bottom painted. I can't imagine that could have anything to do with this problem.