What prop on a 18ft w/a 115 tower of power

[earringboy]

Re: What prop on a 18ft w/a 115 tower of power

Ordered the Solas Amita 4 in12 3/4 x 17p. probably won't get here until Monday afternoon. I think it will hit 5600rpm with a light load, I guess I would rather be slightly under proped and watch the tach than not have enough power to go and strain the motor. we shall see

 

[trendsetter240]

Re: What prop on a 18ft w/a 115 tower of power

Ordered the Solas Amita 4 in12 3/4 x 17p. probably won't get here until Monday afternoon. I think it will hit 5600rpm with a light load, I guess I would rather be slightly under proped and watch the tach than not have enough power to go and strain the motor. we shall see

Good luck and please post back your results!

Cheers.

 

[earringboy]

Re: What prop on a 18ft w/a 115 tower of power

I finnally got on the water this past Sunday. It was pretty windy and choppy, think my tach was acting up. Solas Amita 4, 12 3/4 diameter 17pitch, 5600-5700 and 39mph, but I need to verify all that. I did however think that the 4 blade required more steering effort than the 3 blade. Am I nuts or has any one else noticed this? I have Teleflex 3 turn standard steering, was thinking of going to hydro anyway.

 

[earringboy]

Re: What prop on a 18ft w/a 115 tower of power

Had the boat out again last thursday, steering still seemed very difficult at speed and the boat seemed to be listing to the right at mid to top end. I keep it covered and there was NO water inside the boat, people and gear were pretty well distributed. Could the prop cause these issues?

 

[trendsetter240]

Re: What prop on a 18ft w/a 115 tower of power

Had the boat out again last thursday, steering still seemed very difficult at speed and the boat seemed to be listing to the right at mid to top end. I keep it covered and there was NO water inside the boat, people and gear were pretty well distributed. Could the prop cause these issues?

The new prop is likely providing a different lift profile than your old prop. Probably lifting the stern higher up out of the water.

If it's listing right then you probably have too much of your bow in the water. Try trimming the motor out a bit during mid-throttle range and see if that improves things.

 

[earringboy]

Re: What prop on a 18ft w/a 115 tower of power

Okay, so I am not nuts then, good. Trim it up till I loose grip or speed? I have no trim gauge. Do the steering difficulties sound right, I don't remember the 3 blade being as difficult to steer.

Thanks, it grips awesome from 4000 to 5500, picks up speed right now.

 

[trendsetter240]

Re: What prop on a 18ft w/a 115 tower of power

Okay, so I am not nuts then, good. Trim it up till I loose grip or speed? I have no trim gauge. Do the steering difficulties sound right, I don't remember the 3 blade being as difficult to steer.

Thanks, it grips awesome from 4000 to 5500, picks up speed right now.

My boat does the same thing around 4000RPM if I don't trim out. I can feel the boat flatten out as I trim out and the bow lifts out of the water.

Happens with some 3 blades too. It's all about the design of the prop, some lift the stern, some lift the bow, some lift the whole boat.

It's not a bad thing, it's good to reduce the wetted surface area of the boat so there is less drag.

EDIT: Just wanted to add, trim it up until the prop starts to ventilate (lose grip) and then back in until it stops.

 

[earringboy]

Re: What prop on a 18ft w/a 115 tower of power

Do you have a trim gauge on your boat? Would you reccomend I put one on?

 

[trendsetter240]

Re: What prop on a 18ft w/a 115 tower of power

Do you have a trim gauge on your boat? Would you reccomend I put one on?

I don't have a trim gauge. I don't think they're required unless you can't see and hear your outboard while you are adjusting the trim.

You'll get the feel of it once you've played around with it enough. My boat likes the trim all the way in for holeshot, then once on a plane I trim it out to about even with the hull (neutral trim).

At about 3/4 throttle it will start to lean to the right a bit an I can trim out to make the boat ride flat. At full throttle my boat like as much trim as I can get before the prop starts to ventilate.

You might find that the trim setting doesn't fully correct the issue your having but try it out before looking at other things like weight distribution and the trim tab above your prop.

 

[earringboy]

Re: What prop on a 18ft w/a 115 tower of power

You might find that the trim setting doesn't fully correct the issue your having but try it out before looking at other things like weight distribution and the trim tab above your prop.

I have no trim tab on the motor, it was not there when I bought it this spring. Can it make a big difference?

I do have a trim tab that I can install, came off 90hp that I sold for part, never installed it because I didn't know if it was that important or not. Take it I SHOULD put it on huh?

 

[steelespike]

Re: What prop on a 18ft w/a 115 tower of power

The tab can help counter prop torque. Also will help reduce corrosion of motor lower
end. If the prop is clockwise rotation , viewed from behind, leaning right would be unusual.A deep V boat will sometimes want to run on one side of the V.
If wind was from the right(starboard) side the boat may lean as you steer to counter the wind.

 

[earringboy]

Re: What prop on a 18ft w/a 115 tower of power

We did have a good breeze that day. It is hard to do testing with the wife and kids onboard. I will put the trim tab on, I am guessing it should be straight to start with and see what happens. I am also going to replace my steering with a Baystar hydro as soon as I get the money, that should take care of the steering difficulties.

 

[earringboy]

Re: What prop on a 18ft w/a 115 tower of power

38.6 mph @5500-5600rpm into the wind with the 17p 4 blade aluminum Solas Amita 4. Didn't test with the wind at my back, wife and kids had other ideas of what they wanted to do. Maybe could've gotten more if I trimmed up further.

 

[trendsetter240]

Re: What prop on a 18ft w/a 115 tower of power

38.6 mph @5500-5600rpm into the wind with the 17p 4 blade aluminum Solas Amita 4. Didn't test with the wind at my back, wife and kids had other ideas of what they wanted to do. Maybe could've gotten more if I trimmed up further.

Well your prop slip has dropped to a much better level and your RPMs are right on where you want them at WOT. Seems pretty good to me.

How is the hole shot with the new prop? Does the prop lose grip at all in turns?


Cheers.

 

[earringboy]

Re: What prop on a 18ft w/a 115 tower of power

Hole shot seems real good, 4000rpm to WOT is awesome. I have not been able to test turns at all, my wife gets a little squirly if I start goofing around. I need to get out with a buddy to do that, plus the last few times we've been out the lake has been kinda busy. Pretty happy with the prop, I will have to see if the motor is high enough, and how far I can trim it out, might be able to step up to a 18p 4 blade in stainless at some time. There are many things on my wishlist and another new prop is a ways down. How tight do you recommend testing the turns and at what speed?

Thanks for the help Trendsetter240

 

[earringboy]

Re: What prop on a 18ft w/a 115 tower of power

Okay, so I decided I don't like the Solas Amita 4. Seems really hard to steer and seems to push the boat into waves. It's a 17p if anyone is looking. I think I'll try a 19p 3 blade Quicksilver.

 

[earringboy]

Re: What prop on a 18ft w/a 115 tower of power

Picked up a 20p stainless Quicksilver Laser II, anyone have experience with one of these?

 

[earringboy]

Re: What prop on a 18ft w/a 115 tower of power

Put on a new quicksilver 3 blade aluminum with the flow torque hub. What a difference in handling! Way better steering, topped out at 41.4 mph @ 5500 rpm. The amita 4 sucked compared to this prop.