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Greetings all,

I'm getting ready to re-power my 1986 18 Outrage with a Suzuki 140. If anyone has this motor on a 18 Outrage I'd be interested to know what prop you are using. Also, anyone know what motor mount hole should be used?

Thanks,
Mike

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Mike,

I'm currently looking at the same repower option.

Tom Clark suggests a stainless Suzuki, Turbo or Yamaha 14x18 for me, but I'm at elevation. I've also seen him suggest the same design, but in a 14x20 to others with an Outrage 18.

I'll be watching this thread to hear how it works out for you.

Mark

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I have a Suzuki 140 on my 1992 outrage 19 I. Same hull as outrage 18. I am currently using Suzuki stainless prop. 14 x 22. Part # 99105-00700-22P. Performance was not maximized with the small pitch.

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What does that mean?

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During the initial trial run, a 14 x 20 prop was used. The motor appeared to "cavitate"....high rpm and low top end....boat did not perform as expected. Replaced prop with the 14 x 22, which seemed to correct the feel and performance of the boat.

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OK, got it.

How fast does your boat go?

What year is your DF140?

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Suzuki df 140 is 2012. Top end is 42-43 mph.....

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A DF140 turning 6200 RPM and hitting 42.5 MPH with a 22 inch pitch prop yields 15 percent calculated propeller slip.

That surprises me.

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I'm not quite sure...I think my max rpm is around 6000. My mechanic was also surprised with required increase in prop size. I looked at Suzuki's performance data with the DF 140 on similar size boats....they also used 14 x 22 sized props....?

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Perhaps this teaches us that the Suzuki brand prop pitches do not directly translate to the Stiletto and Turbo pitches.

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There are some 10 year old posts about Outrage 18's being powered by the first-gen DF140's (2.38 gear ratio) on CW. I think I've seen 2 owners who were claiming 42-44mph WOT using an 14.25 x 18 4-blade Powertech prop. Applying the gear ratio change, we would require a 19p or 20p on the 2.59 gear ratio engine.

What are your thoughts on this Tom?

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If the boat is going to run 43 MPH and the propeller yields 5 percent calculated slip, then 20" pitch will be required.

If the propeller model yields -5 percent slip (as most Advantage 4.25s do) then 18" pitch will be required.

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Interesting. I didn't realize one could expect negative slip and plan accordingly with prop selection.

In researching this engine, it seems to have (as many have noted) very similar performance to the DF115 to 5000rpm or so, but the top end is 10-20% stronger, depending upon the application.

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I've returned from study mode and think I may now understand what you mean: The calculated slip we are discussing is theoretical, since we cannot easily measure actual slip.
So a calculated slip of -5% indicates the 18p Advantage 4.25 typically behaves like a 19p prop, but if calculated slip is +5%, then we're talking about the 20p prop behaving as if it were 19p. Am I warm?

My previous question was poorly worded...I was more curious about your opinion on the use of the 4-blade Powetech in this application...advantages and disadvantages.

thank you

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I have no experience with the four blade PowerTech! propeller you mention.

I've been trying to explain propeller slip for years. There is so much bad information out there about the term (including from prop manufacturers themselves) I now make a point of saying "calculated slip" instead of "slip".

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Preliminary numbers for the Suzuki DF 140. It has a Suzuki 14”/20” pitch SS prop. Conditions were windy and1-2 ft chop. Full tank of fuel and just me on the boat with normal equipment. I have about 5 hours on it. Planning on running it again this weekend. MPH is with a handheld Garmin GPS. WOT showed 6450 RPM but I didn't leave it their long enough to get any numbers. Thinking I may try a 22" prop?

RPM MPH GPH
3500 20.5 2.5
4000 26.6 3.4
4500 29.8 4.6
5000 33.6 5.6
5500 38.1 6.5
6000 39.6 9.4

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Before you change props, please verify how the engine is mounted.

How many holes "up", or how many empty bolt holes above the top bolt in the bracket.

To do proper performance testing, you need to factor wind, current, temps, sea state and weight.

While not trying to be too scientific, one run is not sufficient to evaluate a prop.

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If say 4.6 gph at 30 mpg fast cruise looks pretty good. I'll have the same boat/motor combo in the water this summer...can't wait!

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I'll confirm this weekend but I believe their are two empty holes above the top mounting bolt.