Low HP ski prop

Ronald1

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I'm looking to buy a stainless prop for 15' trihull with 60 hp Evinrude. What do you recommend?
 

cobra 3.0

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Re: Low HP ski prop

What pitch and prop have you got on now and what is your present WOT rpm. Do you know the rpm operating range for your motor?
 

Ronald1

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Re: Low HP ski prop

My current prop is a 13.25x17. Opperating range is 4500-5500. It will pull 4900-5000 rpm.<br /><br />The question is what is the best ski prop for a reasonable amount of money. I'm looking for a name and a reason. A testamonial would be great. Thanks
 

WillyBWright

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Re: Low HP ski prop

I had a 15' BeeCraft trihull with a 60 triple. 19 was good for speed, but wouldn't yank me out on slalom. I got a 15 and never got a chance to try it skiing, but the boat had a great hole shot with it. 17s are good for average use. I wouldn't spend the money for a stainless on that. The advantages just don't translate well to a midsized rig. I don't think you'd notice any advantage.
 

walleyehed

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Re: Low HP ski prop

4900-5000 RPM is a little low. Best results come at 5500-5600 with that engine. <br />391198 OMC P/N for a 13-3/4X15, the prop I would recommend. It'll put ya in the 5400RPM range which will be alot easier on that engine and will give alot better hole-shot as willy said.<br /> http://www.iboats.com/mall/propfind...tion=Standard&horsepower=60&url_mode=standard <br />Check the link for some good props here at iboats.<br />We also have the option of venting the prop slightly to achieve even more hole-shot(on the 15 pitch) without losing top-end.
 

Ronald1

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Re: Low HP ski prop

Thanks for the replies. I was wondering if I would get noticeably better performance from a stainless prop on my rig. The general concensus seems to be NO. I was seduced by the goddess of the shiny propeller. Guess you saved me @ $200. I think I will spend that $200 on a ski pole. What do you think?<br /><br />If given the choice would you by an OMC aluminum or a Michigan Wheel. Is the Vortex truly a better aluminum prop?<br /><br />I ported my 17p prop and it helped. Still plan to buy a 15p. THANKS
 

walleyehed

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Re: Low HP ski prop

The MWC is nearly an exact copy of blade design and costs much less.
 

Ronald1

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Re: Low HP ski prop

Kenny, Are you talking about a Michigan Match or a Vortex? It's a lot easier to find a place to buy a MW prop than an OMC. Thanks
 

walleyehed

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Re: Low HP ski prop

The Vortex is the same prop with an XHS hub system, both by Michigan wheel. some of this particular issue is explained in the FAQ section, and may help some, but in general, both the Mich. match and the vortex have the same blades, just different hub systems.
 

Ronald1

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Re: Low HP ski prop

I ordered a Michigan Wheel 13.75X15, #011002, today and should have it by this weekend.<br /><br />I still love those shiny propellers and will probably bend your ear some more about them......<br /><br />Thanks for the advice. I'll let you know how it turns out.
 

walleyehed

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Re: Low HP ski prop

Post back with results, and if needed, we can play alittle with some other adjusments..
 

Ronald1

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Jun 2, 2004
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Re: Low HP ski prop

I tried my new prop last Sunday and was a little disappointed. With just me in the boat the motor would reach 5200, a gain of 200 rpm. With 2 adults and 2 kids @575lb it would reach 5000. I was loaded a little heavier than normal and I personaly did not ski, so it's hard to make a judgement on the holeshot. I think it might be slightly better. Lost about 3mph (speedo). <br /><br />I was hoping that by going to a lower pitch my motor would spin-up faster and reach a higher rpm. This new prop is larger diameter than my 17p, 13.75" vs 13.25" and has a slight cup that my old one does not have. I think it has too much "bite" for the HP(60)I have available. <br /><br />What now? Thanks
 

walleyehed

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Re: Low HP ski prop

capt tuna, you mention the older was un-cupped..that is a very important element considering the 15" you just bought is basically the same performance of an un-cupped 17.<br />That's one of those things we can't see through the computor.<br />The diameter increase is common when the pitch drops in aluminum.<br />We should have found the P/N on your prop to verify what we had...I'm sorry now that I didn't get that info...that's a 300-400RPM difference had we got a 13.
 

Ronald1

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Re: Low HP ski prop

My old prop is an OMC #382764. The new prop only clears the anticavitation plate by @.125". I have my doubts that a 14 x 13 aluminum will clear. Stiletto lists a 13.25 x 13. What do you think?<br /><br />Phatman, Thanks for the offer. My Evinrude has the large gearcase, 1970 model.
 

Ronald1

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Re: Low HP ski prop

Walleyehed, What is you're opinion of running the 13.25 x13 Stiletto? Any other sudjestions? Thanks
 

walleyehed

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Re: Low HP ski prop

Stiletto is one darn good prop...I wouldn't have any reservations as to the performance capabilities...I have run several stilettos in the past and they are well engineered, well-built props.
 

Ronald1

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Jun 2, 2004
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Re: Low HP ski prop

I have a question about MPH. If proped correctly, shouldn't I maintain my top speed when lowering pitch (at leaste close)? My thoughts are that the gain in RPM should offset the loss in pitch.<br /><br />With my original 17p prop my speedo indicated 31mph at 5000 rpm. The 15p went 28 mph at 5200 rpm. I'm wondering if a 13p will still keep me in the 28-31 mph range. The boat is plenty fast for a 1969 15' trihull, but I really don't want it to be any slower! Thanks
 

walleyehed

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Re: Low HP ski prop

The SS prop turning 5500-5600 will be more efficient and should show reasonable numbers...<br />The 13-3/4X15 prop has alot of blade area, and loses some on top-end because of it. The SS props generally have slightly smaller diameter, and different blade geometry.<br />I've ran a 17" new, un-cupped, switched to a new 15" cupped, and atttained the same speed within 1 mph, at the same rpm. I could not trim the un-cupped prop very far-reducing efficiency-where-as I could trim the cupped 15 More, lifting the boat for less wetted surface.<br />I think the diameter hurt you in your case with the 15 pitch. The larger diameter will give a bigger "push" out of the hole, but has more "blade-drag" at top-end.<br />I'm going to look up some props and see whats out there that would fit your application in my opinion, and you can take it from there.
 

walleyehed

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Re: Low HP ski prop

Looks to me like the best choice would be a Turbo1, in 13.25X13.<br />A high-quality, top performing prop, and based on the RPM you give with the 15P, this would put you right in the RPM range you need to be in.<br />This prop has the right charactoristics to keep as much top-end as possible too.<br />That would be my first choice with this application.<br /> http://www.turbo-props.com/TURBO1.html
 
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