Propeller recommendation

[bhollehday]

1) Performance issue you are trying to correct.
Slow to plane, no power out of the hull, doesnt max out RPM with more than 4 people

2) Current prop manufacturer, model, aluminum or stainless as a minimum.
Prop was just lost in the river, but it was a 3 blade aluminum and was told it was an 18pitch

3) Current prop diameter and pitch (required).
Unknown

4) Wide open throttle RPM and speed with an average load (very helpful)
4600-5000 RPM

5) Engine/drive make, model, year, and HP
5.0L Volvo Penta, 2006, 270 HP 1.6 Gear Ratio

6) Boat make model, year, length and weight
2006 Larson Senza 206 ,3150lb dry


I was looking at getting a Stilleto Bay Pro II 18p and found a good one locally for $180 with the hub. Its a 4 blade SS prop though and not sure if I like the idea of SS or really need it. Im afraid if I hit something that I might damage my outdrive compared to using an aluminum prop.

Does anyone have any alternatives for a good starter prop? I would like to be able to pull a single skier out of the water with 6 people in the boat. It previously felt powerless.

 

[alldodge]

Howdy

This statement is puzzling in conjunction with the rpm one

Slow to plane, no power out of the hull, doesnt max out RPM with more than 4 people

4) Wide open throttle RPM and speed with an average load (very helpful)
4600-5000 RPM

You cannot reach WOT but then the next statement says you do

To go from a 3 blade to a 4 blade pro you need to reduce the pitch by 2 so looking at 16 pitch. The 4 blades take more HP to turn, give more hole shot but reduce some top end. Another thing with a 4 or more blade prop is there is more lift. More lift means less trim, and if your on the edge to porpoise now, it would not be good to change to more blades. A stainless prop will give better performance but if something is hit, then it could damage the drive and not just the prop.

 

[bhollehday]

Howdy

This statement is puzzling in conjunction with the rpm one


You cannot reach WOT but then the next statement says you do

To go from a 3 blade to a 4 blade pro you need to reduce the pitch by 2 so looking at 16 pitch. The 4 blades take more HP to turn, give more hole shot but reduce some top end. Another thing with a 4 or more blade prop is there is more lift. More lift means less trim, and if your on the edge to porpoise now, it would not be good to change to more blades. A stainless prop will give better performance but if something is hit, then it could damage the drive and not just the prop.

Without knowing anything about the prop that was on it unfortunetly, is it safe to base a recommendation off of this post with the same exact boat? (Anticipating more rider weight)

http://forums.iboats.com/forum/gene...cs/420170-prop-for-a-larson-senza-206-5-0-gxi

I can buy this same prop for new locally for $180, but think I would be better off going aluminum? Not sure where to start though...

 

[alldodge]

Your having a hard time coming out of the hole with a 18-3 blade an you want to try a 18-4 blade. While you have same boat, the extra people will still be an issue. I don't think it will work, you have more blades but same pitch as before.

 

[bhollehday]

Your having a hard time coming out of the hole with a 18-3 blade an you want to try a 18-4 blade. While you have same boat, the extra people will still be an issue. I don't think it will work, you have more blades but same pitch as before.

I was told that it was an 18p but the more i think about it the less I beleive it. I just bought the boat so I dont have much time with it. Judging by the post from the other guy with the same exact setup (2006 Larson 206 Senza Volvo 5.0L GXi 270hp), unless im having engine issues, I dont think its practical to assume the seller really did have an 18-3 on it based off of performance i saw.

When I first got the boat the I had it wide open and didnt notice my top speed or tach with 4 people in. It seemed to plane slow (bow drop and flatten out after initial start). I took it to the river with 7 people (one being towed on ski), and it seemed very sluggish and took awhile for the bow to lower (Plane I think).

Judging off of the other guys recommendations, and being very happy with them, can I pick up any 4 blade aluminum in the same diameter and pitch and expect nearly the same performance compared to a SS prop?

 

[alldodge]

Judging off of the other guys recommendations, and being very happy with them, can I pick up any 4 blade aluminum in the same diameter and pitch and expect nearly the same performance compared to a SS prop?

The aluminum prop will be close to the SS one. SS prop blades are thinner so it takes less HP to turn, and the blades don't flex as much as aluminum so more power is transmitted.

If you could find a prop shop, many loan props for trial efforts

 

[QBhoy]

Is it possible that an 18" pitch is an unlikely size of prop for this application ? Not impossible, but would certainly be unusual.
Also confused by the rpms you are achieving in comparison to the performance description.

 

[Sea Rider]

It's out of this world to pretend go boating with + 6 up while pulling a single skier. Load is an issue here, would you say that you'll be boating with + 6 always, often, occasionally ? If always dial a prop to run at max wot range, just throttle less while with less souls on board for engine not to over rev if doesn't have a rev limiter.

For top skiing purposes you only need 3 souls, skier, spotter & driver and correctly pitched for engine to run at max wot range, wil have excellent boat & skier hole shot. Could dial an extra prop for that sole application.

Will need to invest some money dialing best prop for + 6 up and skiing purposes, only possible while testing on water at speed.

Happy Boating

 

[bhollehday]

It's out of this world to pretend go boating with + 6 up while pulling a single skier. Load is an issue here, would you say that you'll be boating with + 6 always, often, occasionally ? If always dial a prop to run at max wot range, just throttle less while with less souls on board for engine not to over rev if doesn't have a rev limiter.

For top skiing purposes you only need 3 souls, skier, spotter & driver and correctly pitched for engine to run at max wot range, wil have excellent boat & skier hole shot. Could dial an extra prop for that sole application.

Will need to invest some money dialing best prop for + 6 up and skiing purposes, only possible while testing on water at speed.

Happy Boating

So yes thats exactly what im going to do is have one 18/19p prop for cruising and one lower pitch 17p for heavy skiing.

I do have a question though on size / pitch. It seems when shopping for 17/18/19p props, they are come in slightly different diameters. How can I use the size to help me gain what id prefer? What will the slightly smaller or larger diameter size do for performance?

Thanks!

 

[Sea Rider]

Diam depends entirely on what prop manufacturer wants to give to that particular prop, wouldn't worry to much about diam as pitch is all to consider. Less pitch more wot rpm, more pitch, less wot rpm..

Happy Boating

 

[porscheguy]

An aluminum prop isn't going to deliver the same performance as a stainless unless you're getting the most basic stainless you can find.

If your primary desire is good performance while fully loaded and pulling skiers, look at a high 5/qst 5. They're the same. One is mercury branded, the other is quicksilver. They have vent plugs you can play with as your load changes. The high 5 has been a go to prop for water sports enthusiasts for decades. You can probably find one on Craigslist for a fraction of new.

 

[Scott06]

Since you don't know what you had in terms of pitch and wot rpms I'd start with aluminum. Your set up is basically what I have and use is similar ( lots of people and water sports), my sea ray 200 is 21 ft/3200 lbs. to get a baseline I'd try a Michigan vortex 4 blade in 18"(just over $100) , I think the hole shot and cruise will be nice. As stated above if it's all skiing all the time try the high five or a 16" 4 blade.

Do you have a local prop shop who will let you demo props? I did that and ran two different pitches over a weekend, of course bought them both

 

[bhollehday]

So I just got back from a trip last weekend and ended up using a 4 blade 17p aluminum prop. Was much more happy with it compared to last trip with the "supposedly" 18p prop. I had 6 adults 2 kids and one baby with some gear. I was about 40 mph when the tach finally got to 5K. I barely backed off it just a bit to prevent it from hitting the limiter.

Along with the 17p I also bought a 20p 4 blase, I can return if needed for something else if I dont use it, but I wanted to know if a jump from 17p to a 20p might be too flat of a prop.

I think i like the idea of a 17p for heavy skiing with people aboard, as all skiing will be done with at least 3-4 people on the boat (4-5 total with skier), and regardless of top speed I want hole shot power and quick plane. But id also like to have another prop for weekends without skiing and maybe 4-6 adults and no gear. Something with top speed and not really hole shot or quick plane. Should I just go try out the 20 or does anyone think i should do a 19 instead?