# 18 Waterman Yamaha 70tlr what prop



## redchaser (Aug 24, 2015)

I need to re prop, 18 foot waterman, Yamaha 2 stroke 70, Jack plate. Suggestions on prop, model/pitch? Preferably something off the shelf like a PowerTech. I don’t do enough critical super shallow water running and jumping up to really justify a custom prop like a Foreman/Baumman etc.


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## ElLobo (Sep 14, 2020)

Powertech SCD3 r16 or r17. I have the same engine and boat and run the r17, maxes out at 5800-5900 rpms and I get about 38 mph WOT


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## DBStoots (Jul 9, 2011)

I have a 2007 Gordon Waterman 18, running a Yamaha F70. Prop is a PowerTech! 3 blade. I can't read the model number, but here's a picture. I have hit 40 mph and generally run 5200 to 5500 RPM at about 32-35 MPH. Hot shot is really good.


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## redchaser (Aug 24, 2015)

I found a great deal on a “demo” Yamaha Black Stainless 17p. Similar characteristics as an SCD but from what I’m reading bites better, can be run higher etc.


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## DBStoots (Jul 9, 2011)

redchaser said:


> I found a great deal on a “demo” Yamaha Black Stainless 17p. Similar characteristics as an SCD but from what I’m reading bites better, can be run higher etc.


How are you liking the Yamaha prop? How's the performance?


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## ElLobo (Sep 14, 2020)

DBStoots said:


> How are you liking the Yamaha prop? How's the performance?


I've got the power tech SCD3 17P. I get about 38 mph at WOT 5900 rpm no jackplate. Cruise at 32 mph at 4500 rpm. Still get on on plane in one boat length with the 17p which surprised me. I was running the yamaha stainless 14p before. Would hit the rev limiter around 5400-5500 rpm with the prop. I think the 16p scd3 is the sweet spot prop for the 18 waterman with yamaha 70, but the 17p has been great for me. I dont see much loss in hole shot or running heavy loads with it.


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## ElLobo (Sep 14, 2020)

DBStoots said:


> I have a 2007 Gordon Waterman 18, running a Yamaha F70. Prop is a PowerTech! 3 blade. I can't read the model number, but here's a picture. I have hit 40 mph and generally run 5200 to 5500 RPM at about 32-35 MPH. Hot shot is really good.
> 
> View attachment 177164


Looks like you have the PTR3 13P David.


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## DBStoots (Jul 9, 2011)

ElLobo said:


> Looks like you have the PTR3 13P David.


Wonder how the performance would change if I went to a 15 or 16 pitch? I also have a spare 4 blade (SCD4R14) that I once had for a Professional. Wonder how that would perform?


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## ElLobo (Sep 14, 2020)

DBStoots said:


> Wonder how the performance would change if I went to a 15 or 16 pitch? I also have a spare 4 blade (SCD4R14) that I once had for a Professional. Wonder how that would perform?


You would get more top end if you went up a pitch or two. I believe the PTR provides more bow lift and the SCD more stern lift. I think its better for getting the stern up and running shallow but it might be negligible. I have a buddy with the Beavertail B2 ( same hull as the waterman). His seems to run similar to mine and he has the PTR3. A 4 blade will get you more grip and hole shot (better for running under a heavier load) but a lower top end. If I was to get another prop for my waterman I would drop down to the SCD3 16p, but I'm pretty happy with the 17p for now.


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## DBStoots (Jul 9, 2011)

Gonna try the SCD4R14 this week and see how it does.


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## DBStoots (Jul 9, 2011)

Ran the PT SCD4R14 on the Waterman today--I was very pleased. Hole shot is even better (and it was really good before), and I hit 6300 RPM and close to 40 MPH (solo, but full tank of fuel and full gear). Skiff handled great, did not slide in the turns even at high speed. One thing I did note is that the skiff ran more bow down, even when trimmed up. Not sure if the improvements to the Atlas Micro Jacker operation impacted performance or not (I am now able to run the skiff with the jack plate all the way up). Seems to run best with the jack plate up, and the motor trimmed up a bit too. Never had to worry about water pressure.


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