On way home on 500 mile trip with new used boat. Engines ran fine for 2 hrs. Then they started slowing down little by little at different times. Limpd in at 900 rpm. They're racor 500 FG filters. Says to use element 2010 series. Never saw water in bowl. Will open up n see elements. Found 2 new on board that are 30 microns. The engines are Perkins Sabre M300TI TI. Secondary on engine is Perkins 35412 & just found on on board. Could anyone please link me up on what to do aftet swapping out Racor element to get rid of air etc. Thanks