I have a 1996 Astro 18.5" with a mercury 150 efi that i just bought. The boat runs real well . Old tach was bad installed new quick silver tach. The problem i'm having is the boat only runs at 4900 rpm and gps at 56.9 mph. The boat is fast enough for me but the engine redline I belive is 5400 rpm. It doesn't matter if I have 2 people in the boat or 1 with a full tank of fuel or:% almost empty same mph and rpm. Motor trimmed up all the way watching rpm and gps to see if i'm losing mph but i'm not. And the boat diggs pretty deep on the hole shot and doesn't get on plane to fast. It has a trophy 25p prop
