HI everybody im new here and new to boating so please bear with me if I use the wrong teminoligy. I was recently given a boat. I fixed a hole in it and put a new prop on it and took it out for a test drive. The prop I put on was the same as the one that came off the problem I am having is when I start the boat on land ( With earmuffs) the thing runs great. It sounds like it gets to about 5500 rps or so (No tac). When I take it in the watter the frint end comes up pretty high and the motor ony sounds like its putting out 2500 rpm's. If you throw some weight in the front the boat picks up speed. I set the engin on the lowest setting and it seemd to help a little but not much. The boat was sitting for 2 year and maintined pretty well before it sat. Im going to change out the plugs today see if it helps. Also there was three wires inside the engin that were broken. Two went to the stator and one went to a sensor under the stator that attches on the crnak. I replaced the three wires. The boat is a 1970 winner modified v hull 18foot and the engin is a 1986 75 hp merc 4 cyl. There was about 3 gallons of gass in the tank when i got it, it was starting to turn so i added 15 gallons of fresh hightest and oil. I see alot of people on here telling others to pump the primer when at full speed. Havent done this yet just wanted to know the logic behind it..... any sugestions would be greatley appricated. the prop is a 13.25x17....... dont know if its an engine problem or a prop problem....... boat weighs aprox. 2000 lbs....
