My grandfather has recently given me his 2001 Yamaha 15HP and a Crestliner boat. After using the boat i noticed a problem with more that 2 people my top speed was about 17kph, with me alone is 44kph. When there is more than 2 people in it , the motor sounds like it isint revving up. The prop is stock. When i pulled the motor out of the water the ground wire near the lower unit looks like it was fried as all the protective coating to it look as though it melted. please reply as the motor has no power. The motor always runs but with 2 people+ it dosent rev.
