I have a 60 hp mercury on a 24ft pontoon and I am wondering if the prop is the right size for the performance on it. Prop size 10.75?12. I get about 25 mph top speed with two people in it
What year Merc? 2 stroke? 4 stroke? Without the rpm You can't correctly change props. Is your speed by gps?
Apparently you increased the Diameter. 11 3/8. This may further reduce the rpm. But we don't know where it was in the first place
except that the 12" is likely too high causing the motor to lug.Very bad. We need the rpm and the speed by gps .
Prop size is written Diameter X pitch. Roscoes suggestion 11" X 9" is reasonable based on experience.