1974 18' Sea Sprite 165 Mercrusier My dad has owned this boat since it was new.

[MeBeaTiger]

He had the prop rebuilt in the process they lost the prop. They gave him another prop 14.25 x 19. The boat used to run around 30 mph at 3300rpm. Now according to gps it is running 25 at 4300. How do I know what the correct prop this boat? Thanks

 

[jestor68]

Re: 1974 18' Sea Sprite 165 Mercrusier My dad has owned this boat since it was new.

Was that 30 mph @ 3300 rpm wide open throttle? I hope not.

A 1.65 gear ratio with a 19 pitch prop turning 4300 rpm with a 12% slip would work out to about 41 mph, and run about 30-31 mph at 3300 rpm.

It sounds like the prop shop gave you a bad prop; most likely with a slipping hub.

 

[MeBeaTiger]

Re: 1974 18' Sea Sprite 165 Mercrusier My dad has owned this boat since it was new.

It was not at wide open throttle he never run it much past 3500. I figured that there was something wrong with prop thanks for the time.