Sukuzi DF50 Prop

[Dullboy]

I have looked through the archives and and am thinking that a different prop would probably work better but I am feeling utterly confused.

Currently. I have the a 11.25 x 9 3-blade aluminum prop and can easily go over the governor limit at WOT. I am thinking perhaps a 12/12.25 x 9 prop, or 12/12.25/10 should reduce my revs and add more thrust.

I have also read that some recommend a 4 blade prop and/or even stainless steel. I see where BWY has their "recommended" 10 inch based upon their tests, but $150.00 seems quite steep for a basic 3-blade aluminum prop.


I guess the questions are:

1. Should I be trying to reach top rpms @ WOT, or target top recommended range (6500 rpm) at less than WOT as I have now.

2. What is the ideal prop for this engine providing the ideal rpms/thrust given the answer to the first question.

3. How is stainless necessarily better than aluminum

4. Would 3 or 4 blade be better. Perhaps this is a 3 is better for top end, but 4 is better for low end control.

Dave

[Norm]

Your RPM's should be between 6000-6500 at WOT. Assuming you have a 26X, the prop that will get you right in there would be a 11.75 X 10, 3 blade. I don't know what effect a 4 blade would have, or the merits of aluminium vs stainless.

[Robert]

I tested 9 props with my 1999 Suzuki DF50 on my 1999 Mac26X. I recommend the 3 x 12.25 x 9 pitch prop. Yes, with ballast empty the WOT RPM will be around 6800, but with full ballast the WOT RPM will only be 6350 or close to that depending on loading and waves. I had a talk with my Suzuki mechanic and the Suzuki foeld rep about the 6800 RPM, they both agreed that the Suzuki DF50 is perfectly happy running up to 7000 RPM 24/7, with no ill effects. The four valves per cylinder and coil over plug design favors the higher RPMs. The advantage of the 3 x 12.25 x 9 pitch prop in rough water or near the docks is much better control.
..
The 4 x 11.8 x 9 pitch Solas prop will give you nearly the same 6800 WOT with an empty boat, but slightly higher 6400 with full ballast. The four blade prop is smoother especially at low speeds for trolling or slowly getting out of the marina. The Solas 4 blade prop is pressure cast aluminum and will ring like a bell when struck, it also rings slightly at exactly 2000 RPM.
..
The stainless prop was a test I did out of curiosity, I found it was nice looking when on the trailer and has wider openings for exhaust and very large blades which are thin but more rigid than the aluminum prop. The stainless prop had a slight advantage in performance over the 4 x 11.8 x 9 and I liked the look of it, so that's the one I prefered to keep on.
..
Weight, the Solas 4 x 11.8 x 9 seems to be half the weight of the Suzuki 3 x 11.5 x 10 pitch which seems to be half the weight of the 3 x 12.25 x 9 pitch stainless. This is because the 4 blade uses a different hub slip device than pressed in rubber that the other two use.
..
What prop would I buy today? One that was not available, but that I asked Piranha Propellers for when testing the others. Piranha Prop 129C on this web page: http://www.piranhapropellers.com/Suzuki.php They rate it for a top speed of 19 to 22 MPH which is correct for the Mac26X.

[Frank C]

I guess I've followed Robert's prop testing for at least five years (beginning on Heath's predecessor forum). There is simply nobody who has put in more time and thought on your question than Robert. IMO, you're lucky that he's watching the forum this week - I think he sold his Mac over a year ago (eh, Robt?) - and even luckier that Robert had the same motor, a DF50.

I experimented with Piranha props for my Suzuki DF60 well before Robert started his testing project. At that time the choices were less than ideal. However, I bought their 14x12, plus two more sets of alternate blades. One day the wind pushed me into the rock-reinforced channel bank. Exactly as described on Piranha's website, the prop took the hit, sheared off one blade, and (presumably) protected the gearcase. I switched over to a different set of blades and headed out for a day on the water, about ten minutes later.

Considering Robert's endorsement, I'd phone them in San Luis Obispo and order his suggested prop. You could also send them your well-described scenario by email, but I seriously doubt they can advise you any better than you've already heard. One final suggestion ... if top speed is not your major priority, I'd recommend trying both the Piranha 3-blade and also Robert's 4-bladed choices. The difference of a 4-bladed prop, IMO, is a sort of silky smoothness ... akin to the feel of driving a Chevy versus a Lexus. You should find that you appreciate either one as a big improvement over your current prop.

[Dullboy]

I couldn't find any reference to that particular Solas prop on the internet, and would sure like to try one out.

In the meantime, I really like the idea of the Piranha prop. I'll get it ordered.

Thanks Robert and Frank. You have hopefully saved me from spending alot of time on something I'd rather not do.

btw Frank, I have installed the BRM-2 roller for my Bullwagga. Sweet. Gotta be some kind of rubber man to get your hand up under the peak. Couple that with 98 degree weather here. Oh, what fun. I'll get a picture uploaded as soon as I get a chance.

[Robert]

Yes, sadly, I sold my Mac26X a while ago, and I miss it a lot. This year my daughter's Y-Princess tribe and I will be building a boat from scratch using this boat plan modified slightly to build a kit for quick assembly on a Friday night to be raced Saturday morning with the whole tribe aboard paddling.
http://www.jwboatdesigns.co.nz/plans/cl ... /index.htm
..
The props Solas makes are best viewed on the Honda web page. Solas can put in a hub to match your brand of outboard. Order from Honda, if they will fit the right hub for you, or seek a local Solas dealer and describe the prop you found at Honda's web page.
http://www.honda-marine.com/catalog/pdf ... ellers.pdf
http://www.solas.com.au/suzuki_outboard.asp (ask for Steve Evans at Solas he is knowledgeable about Mac26X even though he's on the other side of the planet from the Mac26X factory)
..
I have found both Piranha and Solas people very nice to work with. They will discuss your particular situation and offer their best recommendations. They also are very good at keeping customer satisfaction as the number one priority for returns or customizations.

[Frank C]

btw Frank, I have installed the BRM-2 roller for my Bullwagga. Sweet. Gotta be some kind of rubber man to get your hand up under the peak. Couple that with 98 degree weather here. Oh, what fun. I'll get a picture uploaded as soon as I get a chance.

Good on ya, DB. I still have a cervical crick caused that day!
Glad it works for ya, and I'll like seeing your pix.

[Tom Root]

How else can I say it, the fine folks at Piranha have made me a happy boater. I really don't think it's a Ford/Chevy brand type issue either!

Their customer service and guaranteed satisfaction is beyond compare. The construction, fit, performance and durabilty is great! And I have tried working with others. With the exception of Solas, I am sure I have had at least one model of all the aftermarket manufacturers!

If I am ever in the market to outfit another application in the future, it will only be a Piranha Prop.....hands down!