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Old 08-31-2019, 07:43 PM
SickWix SickWix is offline
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Default Prop recommendations 18sf

I have a 18sf bracketed with a 96 mercury 150 XR6 2 stroke, currently spinning 5200 rpm... what props are you guys running?
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Old 09-08-2019, 12:05 PM
jctj123 jctj123 is offline
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soon to be dippping my rebuilt 18 with bracket and vmax 150, wat kind of performance do you see with 150 and bracket any pics of urs in the water love to see more 18ft bracketed boats.
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Old 09-09-2019, 06:59 AM
uncleboo uncleboo is offline
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13-1/4 x 21p cupped. I get 40 mph at 6100 with the df140.
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Old 09-12-2019, 06:04 PM
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Fr. Frank Fr. Frank is offline
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Quote:
Originally Posted by SickWix View Post
I have a 18sf bracketed with a 96 mercury 150 XR6 2 stroke, currently spinning 5200 rpm... what props are you guys running?
What prop are you currently running?
Do you have the smaller (4.25") gearcase [optional on the XR6], or the regular large gearcase (4.75")? 1.87 or 2.00 gear ratio?

If you're running the large gearcase with the 1.87 gear ratio, AND you are looking for top speed, I'm going to recommend you look in the neighborhood of 14.5"-15.25" diameter with 19"-21" pitch in a 3-blade offshore prop. Offshore, 3-blades are best when paired with trim tabs.

The PowerTech OFS3 is my first choice in a 3-blade, and the Tempest Plus and Mirage series are good props from Mercury, as is the Solas Titan 3.

If you're running the large gearcase with the 1.87 gear ratio, AND you are looking for economy, handling, and all-around performance, then I'm going to recommend something in the 14.25"-15.25" diameter range with 17"-20" of pitch in a 4-blade stern-lifting prop.

Here I'm a huge fan of the Powertech OFS4, as it's very forgiving of motor height variation. The PT SFS4 is a great all-around 4-blade, especially for smaller boats running V6 motors. Mercury's Revolution 4 is great for stern-lift and maneuvering, but not as good at running trimmed close to the surface.

I used to run a PowerTech OFS3 on my XR4 mounted on my Seafari 20. I had the 1.65:1 gear ratio lower unit with nosecone and low water pickup installed on my motor, and my powerhead had been blueprinted, balanced to .5 grams, and polished, so was producing about 240 hp on the hydro-dyno.

With the OFS3 I gained in hole-shot, top speed, and economy over the Mirage 15x19 I had been running. As the OFS4 series was brand new back in 2003, they made me a custom prop, 15.25"x16.5". I went from turning 6050 rpms at 44-45 mph trimmed out lightly loaded with the Mirage to turning 6150 rpms at 53 mph trimmed out light load, and turning 5800 rpms at 48 mph trimmed out with full load of fuel and 4 people. I went from an overall average of 1.7 mpg with a cruise of 2.7 mpg with the Mirage to an overall average 1.9 mpg with a cruise of 3.0 mpg with the OFS3.

Needless to say, I'm a big fan of Power Tech propellers.
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