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It's only been 3 weeks since first launch and already found the 'hard' w/prop. Fortunately at lowest rpm.
My assigned slip is a sidetie between dock and rip-rap lined edge of marina. Upon transiting to sidetie, left in gear as I drifted a foot or two to wide and DING! Motor shut down and prop has a nice 1/16 inch undulation on two of the blades.
So I'm thinking new replacement Yamaha 13.25x15k aluminum, and new hub?
Or, is now the time to go stainless.
Haven't run it since the Ding, for fear of undue wear on shaft bearing.
Have already abandoned Oceanside Marina for deeper, more room in Mission Bay (san diego), for less money!
But, now conflicted about aluminum or stainless replacement. And, if needed, would it be a good time to update the hub to a better product (whatever that may be), or just stick w/yamaha.

Was still in 1st 10 hours.
Never even spun it up to 5k to see what it's like.

Suggestions?

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Sorry to hear about your incident. Fortunately, despite the prop damage, it's a mild incident for you. If you're going to hit something with the prop (and everybody does), it doesn't get much better than dead idle. The decision whether to go stainless is ultimately a personal one. I'm a big proponent unless there are a lot of underwater obstructions in areas that you will be running at speed. If you'd had a stainless prop in this particular case, the motor still would have stalled but you likely would not have had damage that would be visible or even perceptible (e.g. by increased vibration in the prop). If it was metal that you hit, then perhaps you'd have a small nick in the leading edge of a blade that could be smoothed with a hand file. In my last boat, I was at dead idle going through a swampy canal between two lakes in north central Florida when the prop smacked a log laying across the bottom, stalling the motor instantly. Mind you, this was a 400+ hp big block so even at idle it didn't exactly hit the log lightly. I shrugged my shoulders, fired it back up, noticed no vibration in the prop, and took off after getting through the canal 10 mins later. Took a look at the prop a little later and saw zero damage. And my prop was no stronger than the stainless one you'd have on your boat.

Everything gets better when you go stainless except the initial cost. You will have less damage and fewer repairs needed to a stainless prop. It may be the last prop you ever buy. Now if you happen to have a BIG hit while running, there is the real potential for damage to the rest of the motor that might be avoided with an aluminum prop. I've always been willing to take that risk given the benefits of running SS. It has only hurt me once in 25+ years. About 25 years ago, I was driving the boat onto the trailer at a difficult ramp. I had to give it more gas than usual because of conditions, bringing it up to 2500 rpm. I hit something hard, but still got the boat on the trailer. When I pulled it out, all three stainless blades were bent at 90 degrees. There was no other damage. In fact, the repair cost for the prop was probably about the same cost as buying a new aluminum.

Good luck !!

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go stainless and never go back..

Keep the dinged prop as a spare.

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Where to start:

1. Remove and have prop shop dress edges of current Yam alum 13.5 x 15K prop and continue to experiment w/performance until break-in is complete?

1A. Remove and self dress [fine hand file] edges of current Yam alum 13.5 x 15K prop and continue to experiment w/performance until break-in is complete?

2. Do either of above, and upgrade hub to 'Flo-Torq II' system?

then later:

3. Replace same spec prop, but in SS?

or

4. Replace for SS with different specs [diam-pitch combo] based on full performance data [post break-in w/full equipment on board]?

Thanks for comments-suggestions.
Joe

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EDIT:
I should have prefaced this thread w/make-model year.

The subject Yamaha F70 is a 2014 and the prop installed is a Yamaha aluminum 13.5 x 15K. [not 13.25 as I mis-stated originally]

This is all on a 1987 BW 17' Custom [x SSport] which current weight estimate = 1800lbs w/2 adults. [also excludes 10gal bait tank and 50lb ice chest].

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In retro, I should have titled this thread:
Aluminum prop Ding? Is it worth repair?

I'll post pics later.

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Clean up the prop (like to see a photo to confirm slight damage) and use it till you have determined if it is the right pitch for your needs.

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It's hard to evaluate. As long as you haven't lost any material from the existing prop, it should still be in balance, so it won't hurt the motor to run it. Make a test run and see how it goes, then evaluate your options. Of course you'd want to try a range of RPMs, and be alert for any vibration or other misperformance.

Presuming it works OK, I'd stick it in the spares box and get a nice stainless - no sense burdening a brand new motor with yesteryear's technology. Stiletto Advantage in 13.25x13 should be about perfect for that setup.

Tim

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I put a Yamaha Performance Series 13.25 x 14 prop on my F70 on my 1999 Alert 17 as recommended by Tom Clark and it seems to be the perfect prop for the 17 ft. Hull.

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Tedious,
From what I've seen on the Yamaha prop app chart, there are only 2 Yamaha 13 pitch props listed for my gear case (4.25inch) and HP.
One is an aluminum 13-5/8 diam., the other is SS specified as a Pontoon Performance Series 14 inch diam. Not that I'm opposed to non Yamaha products, but I'm not sure if your recommended 13 prop would be a top end [both rpm and top speed] limiter on a BW 17ft hull.
As stated above, we're likely a bit under 1800 lbs.; less frequently, add bait tank and ice chest and we might be 1900 lbs.
Based on Yamaha Performance Bulletins for the F70, the closest comparables in other hulls [for general comparison] are:
Carolina Skiff 17-9: http://www.yamahaoutboards.com/sites/...14_SKF.pdf
KeyWest 17-4: http://www.yamahaoutboards.com/sites/...b6.tmp.pdf
Sundance 17-10 [this hull is specd as 7ft10inch beam?]: http://www.yamahaoutboards.com/sites/...09_skf.pdf

In the above cases, they were equipped with the standard Yamaha issue 13.5 x 15 aluminum prop and were able to achieve min 36mph and 6300 rpm.
Also, in the case of your recommended 13 vs. my stock alum. 15 is about a 13% pitch reduction with a corresponding 2% diameter increase.
I'm far from competent on propeller knowledge, but it seems at minimum I would want to stay with current 13.5 x 15 but go to SS.
Apparently I'm missing quite a bit.

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Switching prop material or brand/model of props changes everything.

You most likely cannot use the same pitch if you change the material of prop or the brand/model of prop.

At this point, you have no idea if you have the correct pitch prop or not as you have not tested it at WOT.

1. Choose a material, brand and model of prop.
Try a different pitch prop to get your WOT in the motor manufacturers range.
Once you get this within the range, then you are set to go.

2. If you change material, brand and or model of prop, then you have to start all over again choosing a different pitch as most all prop brands and models deliver a different configuration in prop design.

In other words, a 15 pitch prop is not the same across the board.
They are all different.
It also preforms different for other boats and must be tested on your boat/motor combination.

Also, forget about diameter. That is up to the engineers.
When we try a certain brand/model of prop, we try different pitches.
We take whatever the diameter is determined by the engineer.
Example: 13p, 15p, 17p, etc.. We have no choice in the diameter generally. We get what they give us as determined by the pitch.

So, if you change material or brand/model of prop, a 15 pitch will not be the same as the other 15 pitch you have now.

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You've neglected to account for the additional cup on modern ss props which creates greater effective pitch. I run a 13.25 x 15 Stiletto Advantage 1 on my 15 with the F70 and i have found the 17 hull works well with about 2" less pitch than the 15 takes. The Stiletto is an aftermarket prop, but they also make Yamaha branded props if you are looking to pay more for the same chunk of metal.

But as with any prop advice - it's not perfect, trial and error is needed to find the right answer.

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New engines do not include a propeller.

Some dealers "include" an allowance in the price but the selection of size is made by the dealer.

"Included" props for mid-power engines often are aluminum since they are cheaper than stainless.

Boston Whaler buys engines from Mercury, selects the brand and size of prop (stainless) for the application and buys them too.

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I have read the above statement many times in magazines on websites etc.
How do you go about it. An inexpensive SS prop cost $330 to $350, buy one and it doesn't perform like you want so you buy another one and an other one. That is an very expensive trial and error solution.
Isn't the prop selected by BW?

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You don't have to go through a series of props. This question of which prop to use on an F70 mounted on a 17 foot Whaler hull has been addressed many times on this forum. It was mentioned above that Tom Clark reccomended a Yamaha Performance Series 13.25 x 14 prop for another members 17 footer with the F70 engine. You won't find another person on this site more knowledgable about props than Tom. That's the advice I would follow.

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Yeah, theres a truck load I don't know about props- thanks for the info.
As far as the 13.5x15K for new yamaha f70's:
Appears that nearly everyone [that I've heard from here at WC] who has recently purchased one of these outboards, got the 13.5x15K aluminum; looks like we're all spread across the country.
Sounds like a default choice by yamaha, based on least expensive, best 'middle of the road'?

Anyway, I've posted some ugliness of my Yam aluminum w/dinged edges. [cell phone cam- not great images]

http://whalercentral.com/infusions/personal_page/view_personal_page.php?user_id=29977

In the end, I think it can be hand faired, just concerned about running with [damaged?] hub, which at this point I'm not feeeling or hearing any differences from so far.

Looking forward to an SS upgrade by maybe Oct-Nov.

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Good grief, that's hardly worth fixing! Smooth it with some sandpaper, a quick spritz of paint, and go boating.

Tim

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tedious- have been boating!

Just looking for second opinions and didn't want to run above 3000-4000 as is.
My assesment was that there's not enough material displaced or removed to effect shaft bearing, but wanted to ask.
It feels worse than it looks. The original edges were slightly radiused and this just sharpened a portion of each blade edge.
Will try a touch of a fine flat metal file, then maybe some 200 grit.

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Let's be clear,....crystal clear

The recommended prop is a Yamaha Performance series is a stainless steel prop in the 13.25x14 and not just any 13.25x14 prop.

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You're waaay to subtle about this Phil, but I think I'll try the Yamaha Performance Series 13.25 x 14 anyway.

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Yeah, well I kinda didn't think it would be a okay idea for you or maybe someone, like, in the future doing a little looking around, to maybe not pay attention and say buy a Solas 13.25x14 (if it exists) prop and then have a $300 paperweight.

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The truth doesn't have to hurt. Sometimes it's just damned funny.

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Just a follow up about this recent 2014 Yamaha F70 'prop-rash'.

I haven't done anything to dress the edges yet, but I did get in a few hours of run time in varoius conditions and could not feel or hear anything different.

On flat bay water up on 12 mph plane in 4 seconds.

On open ocean, 2-3 swell, 1' chop, 8-10 mph breeze:
3200 rpm = 16 mph
4000 rpm = 21 mph

Speeds from Speedo app on cell phone, but no difference from before 'prop-rash'.

Going to dress prop edge this week and raise engine all the way up from 2nd from bottom to bottom hole of bracket.
After the engine raise and more test runs, I'll look into the stainless prop and likely the Flo-Torq II hub conversion.

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Good decision, it took me 20 years of boating until I had a stainless prop. Once you realize the difference you will just ask why did I not do this sooner.