35 mph

[steplift20]

does that sound right to you
v20 steplift with a 150 merc O.B. turnig a 15x17 aluminum prop
35mph @ W,O,T
if i switched to a s,s, prop how much more should i get in mph

[THEFERMANATOR]

It depends on your current prop. What is your WOT RPM's?

[csvencer]

I am running a johnson 150 with a 15x17 SS prop. WOT fully loaded is around 39-40mph, light load and trimmed up I can hit 45. If you are 35 fully loaded then I think you are pretty good, but if that is trimmed up and light you may want to have the prop refinished.

-Svence

[tsubaki]

I still haven't taken the time to get mine dialed in right.
First prop was a 14x19 stainless, it turned 5100rpm & 42mph, this was a light load in the boat, 20gal fuel and smooth water.
The second prop was a 14.8x17 aluminum, it turned 5000rpm & 41 mph normal load in the boat for 2 people fishing , 40gal fuel and rough choppy water.

[Jetty Rocker]

Sounds like you got your RPM's confused. Normally your RPM's will change @500 RPM's between prop pitches. And If the diameter is the same, you will turn @200 rpm's less changing from an alluminum to a stainless. Maybe this will help.

[THEFERMANATOR]

Originally Posted by Jetty Rocker

Sounds like you got your RPM's confused. Normally your RPM's will change @500 RPM's between prop pitches. And If the diameter is the same, you will turn @200 rpm's less changing from an alluminum to a stainless. Maybe this will help.

The new aluminum series for the OMC engines work like stainless props do for the most part. I ran a 19 VIPIR on my bowrider which would run 47-48 loaded down and turn 5600 RPM's. I then tried one of the newer large diameter aluminums that turned 5400 RPM's and ran 45-46 MPH. The diameter as well as blade design plays a large role in propping. I would think the APOLLO 4 blade in a 16 or 18 pitch would work really well on a V-20 for lower HP numbers. A large diameter like a MIRAGE would work well too probably, but I don't think a V-20 is really heavy enough to really need a 15"-15 1/2" prop.