Excited about our new 21SLX

Pilotnate14

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Finally took delivery of our new 21SLX on a drizzly day last week, and after what felt like waiting a month (2 days), had it out for our maiden voyage. Wife and I could not be happier, was able to dock without hitting or denting anything, and even the dog liked it! It’s gonna be a great September

Anybody else hear a harmonic / “singing” noise from the prop at low speeds just above idle? Dealer says it is propped appropriately and the noise is harmless. Yamaha F150, Quicksilver Nemesis 4-blade 14 x 14 prop. I dunno RPM @ WOT yet, only 3 hrs on it and trying to baby the motor during break-in.
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BigKahuna

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Welcome to the forum Pilot! Congrats on the new boat! What lake do you boat on???
 

BigKahuna

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Thanks! Winnipesaukee, NH
Been there a couple times but it's been a few years.. Very nice! My wife's family used to live on a lake in Rhode Island and my father in law used to fly his plane up there for lunch......
 

DejaWiz

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Nice boat!


I'm anxious to find out what your WOT performance is like after you go through the break-in process.

Safe and happy boating!
 

goldnrod24

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Nice boat!


I'm anxious to find out what your WOT performance is like after you go through the break-in process.

Safe and happy boating!
See my signature for my WOT. 2017 21' SLXP.
 

DejaWiz

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SEMPERFI8387

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Congrats!
 

goldnrod24

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DejaWiz

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Merc 150 with Enertia prop.
Very cool. Sorry...don't know where I came up with you having a Yamaha, other than I got some info crossed/confused somewhere along the way.
 

Al B

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Finally took delivery of our new 21SLX on a drizzly day last week, and after what felt like waiting a month (2 days), had it out for our maiden voyage. Wife and I could not be happier, was able to dock without hitting or denting anything, and even the dog liked it! It’s gonna be a great September

Anybody else hear a harmonic / “singing” noise from the prop at low speeds just above idle? Dealer says it is propped appropriately and the noise is harmless. Yamaha F150, Quicksilver Nemesis 4-blade 14 x 14 prop. I dunno RPM @ WOT yet, only 3 hrs on it and trying to baby the motor during break-in.
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Congratulations
We just bought our 22' SSBX SPS at Winnisquam Marine 3 weeks ago. Where did you buy yours?
Enjoy season is coming to an end fast
 

Vikingstaff

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A belated congratulations. Always exciting to finally get the boat. I hope you are able to squeeze in some fun on it before winter sets in. Happy boating to you!
 

PartyBarge

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Pilotnate, great choice on the pontoon and the dog. Just curious, why do you think the "singing" is from the prop? Any chance it could be a little off-idle intake noise?
 

Pilotnate14

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Pilotnate, great choice on the pontoon and the dog. Just curious, why do you think the "singing" is from the prop? Any chance it could be a little off-idle intake noise?
Hmm.... now you have me thinking.... just what the dealer told me. Noise disappears immediately when I throttle above 1600 rpm. What does intake noise sound like? Thanks!
 

Potomacbassin’

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Apparently singing props are a “thing”. Do a google in The Hull Truth and you’ll see some threads on it. Read that aluminum props are especially susceptible and chamfering the prop edge can solve it. Too much edge modification can be detrimental however so most recommend a prop shop to perform the work. Maybe try a different prop to eliminate the possibility of other rattles and squeaks in the rest of the boat?
 

PartyBarge

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Hmm.... now you have me thinking.... just what the dealer told me. Noise disappears immediately when I throttle above 1600 rpm. What does intake noise sound like? Thanks!
No pat answer for your question, commonly it's a whistling sound as air forces its way past a barely open throttle plate(s). You used the word "harmonic". That's a tip the sound could be from more than one injector bore. Many motors can do that, but it's generally only heard from one that's otherwise pretty quiet. Intake manifolds are usually well muffled for more common intake noise, but not so much for higher pitches.

Check this out. I have heard what I think is a different intake noise from our Stingray I/O (4.3l V6) sometimes with engine deceleration and an aluminum Nemesis prop that is not there with any stainless prop. I initially thought it was a bearing going bad in the accessory drive line. Nope, noise disappeared with switch to a stainless prop (they are much heavier). For our Stingray, it seemed the combination of different drive line inertia and an unmuffled intake was the cause. Note the noise I had was on deceleration not off idle.
 
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