Prop Question on a Mr. Pike/Evinrude Set up

[78cj5]

I have an 06' 16' Lund Mr. Pike with an E-Tec 90. I have run a BRP 14x17 aluminum prop for the first 30 hours. I bought a Stainless 14x17 Viper for it, but when I mounted it, it turns out that the hub was pressed in poorly and was out of round. I brought it back and picked up a 13.25x17 Stainless Turbo since they did not have another Viper.

The performance with the 14x17 aluminum prop was pretty decent. With two guys, gear, and one livewell filled, it ran 38mph(GPS) on the nose @ 5200rpm fully trimmed out with a 3 second holeshot.

With the 13.25x17 stainless prop, I am running at 40.25mph but only at 4800rpm. The holeshot is a tick slower at 3.5 seconds or less. My propshop is willing to drill out the vent holes on the Turbo to improve the holeshot performance. They also said that they would be willing to press a compatible hub into a Stiletto 14x16 prop for me to try if I wanted to do that before they drill the Turbo.

My question is: My performance with the Turbo is good,especially if they can improve the holeshot by enlarging the vent holes, but should I happy with the motor turning sub 5000rpm? The motor feels, sounds, runs smooth as silk and has been put on the computer to make sure everyting is cool. It checked out fine. Or... should I pitch down a bit to see what happens?

[Ralph Wiggum]

Personally, I'd try the lower pitch and see where that gets you before you go getting your 17 drilled.

[cjac]

I have a 115 and I had a hard time getting the RPMs up over 5k with the stainless prop. The aluminum prop weighs about 4 lbs and the stainless was 13 lbs, that's a lot of extra weight to spin. I tried a 1/2 dozen stainless props and ended up going back to the aluminum prop.

The question I was asked by the dealer was "what are you gaining?" I said not much.... kind of sounds like the same applies to you.

[78cj5]

So far, that seems to be the case.

[Chubby]

If a 115 can push several thousand pounds of boat through the water it is certainly capable of spinning a stainless prop up to its proper rpm.

If your O/B does not turn its proper rpm you need to adjust your prop pitch accordingly.

[cjac]

I would have thought so too, it's a 115 Yammy 4stroke on a 17 ft Lund. I've talked to many guys and I have yet to find someone that has a stainless that matches up well on that particular motor on my hull.

Did we just come up with a "Get rich" idea???

[18 inch Crappie]

You motor should run as close to 5500 rpm at WOT to get the most out of your motor/boat as far as speed and hole shot. That motor is rated at 4500-5500 rpm on the web site. So your running 5200 rpms with your stock prop that is where you want to be with SS and that thing should shot out of the water and get you a speed of 40-45 mph. But once they drill that prop it is yours. Get the right size from the 1st place and you should not have to worry about it. Just because they do not have the right size in stock, do not settle, or you will never be happy. My 2 cents

[Valv]

An aluminu prop will flex under load, and change slightly to a shorter pitch, Stainless Steel will not flex, it is a true pitch, that's why it has to be slightly smaller pitch of aluminum.

A good propshop should tell you this, I would sugget trying somewhere else, get a second opinion.

The issue of prop weight has no impact on motor HP, unless we are talking small motors (very small), and if there's a difference it will be very minimal.

Motor should stay around 5000rpm or above, not below.

The question "is it worth it" just to gain 2 mph more is a good issue, especially when you are facing a $ 500.00 bill for a new prop.

Get a SS with a smaller picth, if you can test few brands, different blades styles, number of blades (3, 4, or 5).

[78cj5]

Follow up: I tried a 13.25 x 15 pitch stainless Turbo prop on my E-Tec last night with good results. I lost virtually nothing off the top with a 40.1 average at a much better 5400 RPM. Also, my holeshot was awesome with this prop.

Even though I think this prop is a great fit for the moter and boat, it really didn't improve the performance over the aluminum prop enough to justisfy the difference in cost.

[delcecchi]

So you have a 15 or 20 thousand dollar boat and you are quibbling over a couple hundred bucks on a prop that makes the whole rig work better? Doesn't add up to me.

[slick814]

What doesn't add up to me is the added cost of a stainless prop. As Valv stated, there is no flex under load. That's a good thing. BUT...(and you knew there had to be one) it also won't break off or bend very easily if you happen to hit something solid in the water.

Happened to my brother & me last fall. Taking it easy through a bay where we knew the water was down a little bit, all of a sudden, BAM!... we felt something hit the back end of the boat. Raised the motor, 1 broken off blade, 1 chipped & bent, the third was bent pretty badly. However, after working back over to shore and changing props quickly, we were back on the water and on our way. Had the prop been stainless, I doubt that the lower end would've made it through that reef that we found. I honestly think that the fact that the prop BROKE more than made up for the extra performance that you'd get from stainless, not to mention the saving of some big time repair costs.. is it really worth all of that for 2 MPH? and a .1-3 second difference in your hole shot? Unless you're racing that thing, I wouldn't think so. For most of us, the 2 MPH is about 1 or 2 minutes on most of the lakes in Minnesota. IMHO, not worth the extra costs that you will and can run into with the stainless.

They sure are pretty when they're outta the water, though!

Just my $.02

[78cj5]

The point is, in the end, the performance difference with a stainless prop on this set-up is negligable. A couple of hundred bucks is still a couple of bucks...

[delcecchi]

"ollow up: I tried a 13.25 x 15 pitch stainless Turbo prop on my E-Tec last night with good results. I lost virtually nothing off the top with a 40.1 average at a much better 5400 RPM. Also, my holeshot was awesome with this prop.

Even though I think this prop is a great fit for the moter and boat, it really didn't improve the performance over the aluminum prop enough to justisfy the difference in cost. "

Sounds to me like there was a significant improvement. The question is the justification of difference in cost. My perspective is that the difference in cost isn't much, considering the whole rig. If a couple hundred bucks is that big a deal, how is he gonna put gas in that thing? Better not crank it up. Burn about 25 or 30 dollars an hour or thereabouts at WOT. A couple hundred isn't what it used to be.

[78cj5]

Quote:

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"If a couple hundred bucks is that big a deal, how is he gonna put gas in that thing?

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Your logic is sophomoric. If I am looking for more economic advice, I will be sure to ask you.