Hi all Kinda new here. My problem is: I have a 115 1982 mercury outboard 6 cly rebuilt carbs and checked fuel pump and all new line and tank from eng down. Whats going on is when I give the eng full power she gets up just fine but she spits and acts like she wants to go faster So its like Im going 20mph and then i go 25mph back to 20mph. the boat sounds and runs great at low speeds starts up with no problems. Any ideals? Thanks all