Alumacraft performance

[denpat]

I just bought a 2010 Alumacraft Dominator 175 Sport with a Mercury Optimax 125 and was wondering what kind of performance I could expect out of this boat. I bought it at Cabela's and they had a 13.25 17 P prop on it and I asked them to change it to a 13.75 15 P since I am at 5000' altitude. I went to mercury prop selector and it states that with a 15 P I will only get about 32 MPH. That being said, I put in that I had 1 150 Opti and they still said it would do about 36 MPH. I am now questioning in the numbers they are putting out. I am not looking for high speeds but I would like it to run high 30's or low 40's. When I put it on the water this spring I will be able to tell if I need to go up in pitch. If you have the same boat I would like to hear what your numbers are. I will list the spec's on the boat to see what you opinion might be.

Dry boat weight 1482
Motor weight 375
Fuel capacity 38 gal
I used 900 lbs addition for gear and people.

Thanks for any information you can share with me.

Dennis

[vteye]

Denpat - Alumacraft website used to list specs for various engines and horse powers on the Dominators. My 2010 Dom came with a 115 Yamaha 4 stroke and performance was just as advertised. I think I was doing 39-40 gps with3 batteries, poles, 2 people, an fully loaded boat. Odometer was
indicating mid 40's. I am running factory prop that came with motor.

[Hot Runr Guy]

not sure if you've seen this Mercury report of the 125 Opti on the slightly lighter 175 Navigator Sport, but they ran a 19" Black Max (alum) prop, at only 5450rpm (300 short of redline). I'd have tried that 17" first, remember, the 125 uses a 2.07:1 lower unit, not the 2.33:1 like other 1.5L Opti's.
http://www.mercurymarine.com/engines...letin/?ID=481&

HRG

[nickyneb]

denpat

Congrats on the new boat! I have exact same one (2008) but it has been nothing short of great for me!

I went through the same prop problems/questions as you this last season. If you look up some of my old posts you will see a few of my answers/ideas.

I was living in Denver as well and needed to find that sweetspot for my prop but I also fished tournaments in NE and WY and wanted to know if I was getting the best I could out of my rig. I run a Merc 115 fourstroke and although my motor is heavier than yours I also needed to get up in the higher RPM range for my motor, max rpms (6400). I had my motor set up with a s/s vengenance prop 16p but could never quite make the rpms needed. After alot of research online I dropped down to a s/s 14p and rpms were there(6150-6200) but I would get some porpise(sp?) when I trimmed it out. After more research on Verado owners group website I determined that I needed to raise my motor. That was the ticket and now I could run 38-39mph/gps WOT with 900 lbs gear 2 people and about 1/2 to 3/4 tank of gas.

FWIW I would stick with the 15p, break the motor in properly, see where your rpms are in relation to what the motor should run. Then start looking at your cavitation plate and raise or lower the motor accordingly.

[denpat]

nickyneb

That's exactly the information that I have been looking for. I don't think the 15P is going to be to far off, but I got to questioning my decision. What hole did you end mounting your motor?

Thanks for the info.

denpat

[nickyneb]

denpat,

I moved my motor up.....meaning I now have only one more hole left to raise it if I wanted. I noticed an immediate difference in performance, hole-shot, top-end, and I cannot make it porpose(sp?) at all.

You will do yourself a favor by researching on this website and verado websites as well. They explain where and what your motor should look like when it is running at WOT.

There is also some helpful information on how to raise your motor too. Just be careful, take your time and have all tools close at hand. I had my neighbor help and it scared him good! For liability reasons I think most motors come from the manufacturer mounted lower than needed.

If you don't want to mess with it Bass Pro will do it for you or if you go back to Sidney they can do it as well. I would even help you but I have just finished moving to Canada and it would take more than a case of beer to get me to come over.