Is this a Bravo boat?

Yes , BUT using low water pickups

You may want to try replacing the water hose in the transom assemblies. They could be getting sucked shut. There is also a possibility (if this is a stepped boat) that the hull could be leaving to much air in the water and you are pumping air through the cooling system rather than water. If this is the case you will have to add thru hulls about 4" behind the rear step. There is clean water there. I would start with the water hose though.

You have a bad hose somewhere, as as flow, increases it closes off internally, reduce flow and pressure and it opens back up.

Like when you get a flapper from a bad fitting installation...or the hose could be delaminating on the suction side of the pump.

I've found wood chips in hoses that float around and then finally clog the first cooler enough to restrict water flow. Come to a stop and they must have floated back away from the cooler. I'm not sure that is exactly what happened, but it seemed to resolve my issue at the time.

Did you flush each hose out or just check the coolers?

fixed the problem , long story that would not help this thread caused the problem . thanks for all the ideas to check

I read this and thought the purpose of this site is to help others solve problems. You left us all hanging out in the wind. How does that help those who participated trying to help you?

crack me up . **** off guys I fiqured it out lol congrats glad youre on the water ...

Lol! I thought it... You said it. Oh well.