Prop question

[scott craven]

Found a really good deal on a stainless prop, but the diameter is smaller than the current aluminum by 3/4".
What effect would reducing prop diameter by 3/4" assuming the pitch remained the same ?

I would guess that hole shot would improve, top end would be less ?

 

[adrianna3]

You'll get more RPM but might lose a little speed. I dropped down from a 14" to a 13 1/4" with the same pitch to gain RPM. That way the motor is not working so hard to swing a big prop around. You should be fine with your new prop.

 

[cuttlefish]

I took my prop to a shop when I once wanted to reduce trolling speed without affecting top end performance. The prop shop guy took an inch off the diameter. It had the desired effect. This was on a boat that had a 36" diameter wheel and did not plane. Don't know if that would be the case with a planing hull or a wheel of smaller diameter.

 

[Gypseas]

Went from a 17P alum 3 blade 15in to 17P ss 4 blade 14.5inch
WOT went up 150-200rpm top speed increased by 7-8km/hr ground speed, fuel consumption went down some at cruise.

Seems to cavitate more at holeshot and in rough water and when punching throttle. If throttled up slowly there is no cavitation to speak of.
Food for thought!
cheers

JUST FISHEN'