1995(estimate)30 hp Evinrude not exceeding 10mph

[Ernie33]

I've recently acquired a 13ft boston whaler type boat with a 30hp evinrude engine. The previous owner isn't sure of the year but its estimated a 1995. At first it wasn't starting properly but I've watched plenty of YouTube videos and now I have it running rather smooth and starts up no problem but it doesn't exceed 10 mph when it's maxed out. You can hear it like it has more but then it will die out. Any guesses on what the issue may be?

 

[racerone]

Check the flywheel key.-----Post results of a compression test.----Check spark.----Sounds like it might be running on one cylinder.----You did install a new impeller I hope .

 

[oldboat1]

could also be a fuel issue, or the wrong shaft length for the hull. Was the motor recently installed?

 

[racerone]

It is a long shaft motor.----It appears that " custom work " was done to set motor at the correct height.