hunter 30

[charlescreel]

recently purchased a hunnter 30, 1979 with yanmar ysm12 engine.
prop was replaced with a 3 blade 14/12 prop when the folding prop fell off.

max speed under power is 5 mph but sailing i get 7 -8 mph.

Is this too large a prop for this engine?
Rpms seem low under a load.

[dega1461]

I have the same year boat and motor. That is the best speed I get with the motor running.

[trantor12020]

i read somewhere in these forums that if you can't reach max rpm (or at least 80% max at WOT) under load, your prop is either too large or over pitch.