singing prop?

mrcrw009

Seaman
Joined
Dec 26, 2010
Messages
73
I have just replaced my 11x9 prop with a 10.5x11 prop on a 35 hp evinrude. now it makes a whining noise at certain rpms. the performance works out for me but is this going to hurt anything in the long run and is there any way i can get it to stop whining? Or could it be the drivetrain making the noise?
 

phillnjack2

Ensign
Joined
Apr 30, 2011
Messages
918
Re: singing prop?

when you say its whining, do you mean in the water or out of water testing ?

Have you made sure you have the correct spacer for the prop shaft to propellor ?

Make sure the front of prop is not touching the gearbox and the rubbing making the noise .

Check gearbox oil, change if possible to make sure no water contamination and use correct grade for engine.

if the noise is only at a certain rpm's then it could be badly out of balance !!!!!! if it is this could not only cause a
whine but can do damage to seals in the gearbox.

When the noise happens does the engine show more vibration ? this again would indicate out of balance prop.



phill...............
 

mrcrw009

Seaman
Joined
Dec 26, 2010
Messages
73
Re: singing prop?

it is in the water. and the prop is not rubbing because i spun it by hand and it is free and quiet.the gearbox oil is good. when i put the old prop back on that is no dought out of balance and has been for a while it is fine and the noise stops. the other prop is brand new so i dont think it is out of balance but i guess it could be. do you think that the old prop messed the seals up now that the prop is in balance it is not riding the same on the seals?
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: singing prop?

All I can say is find another new or loaner prop and try that. Never heard this one before. Whining ????
 

etracer68

Ensign
Joined
Oct 11, 2009
Messages
906
Re: singing prop?

The prop shouldnt be coming in contact with any seals. I would try another new or differant prop. What are the rpms when its doing this whining? Are you sure the new prop is for the motor, and its tight on the shaft. There should be a very small amount of play in, and out on the prop shaft, but nothing on the prop to shaft. Sounds like a gear whine to me, but I cant hear it. Also, are there any wear or rub marks on the prop forward outside or inside hub?
 

EddiePetty

Lieutenant Junior Grade
Joined
Aug 25, 2008
Messages
1,008
Re: singing prop?

.........when i put the old prop back on that is no dought out of balance and has been for a while it is fine and the noise stops.

Remove the prop and take run-out and side-to-side 'slop' readings on the prop shaft.

I kinda believe the old prop has done the damage and the 'singing' you're hearing with the new prop is the new (and probably in balance)prop self-centering in all the free play. :)
 

mrcrw009

Seaman
Joined
Dec 26, 2010
Messages
73
Re: singing prop?

yes the prop is for the right motor and i don't know the rpm's because it is a tiller and i have no gauge. i will make sure nothing is rubbing and check the free play, but i think EddiePetty is right and the old prop did the damage already because the old prop looked like it had been through a wood chipper. I have a feeling it is in the gears or something. thanks for all the comments i will let you know what i find out.
 
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