Partially Spun Hub Vibration?

R Socey · Jan 11, 2011

Could a partially spun hub be responsible for a periotic vibration; it was only discernible at very low rpms. in foward gear?

Outsider · Jan 11, 2011

Re: Partially Spun Hub Vibration?

My experience has been that hubs are either spun, or they aren't. I'd look for the solution elsewhere ...

Bondo · Jan 11, 2011

Re: Partially Spun Hub Vibration?

Ayuh,... I'm with Outsider,... In my experince, a spun hub is just that,... Spun...

But,... Changing the prop out is still the 1st step in diagnosin' it...

R Socey · Jan 12, 2011

Re: Partially Spun Hub Vibration?

I heard that a prop can slip, and catch - youre right, I intend on
on having them done up - I'm just hoping that might be the problem.

Robbabob · Jan 12, 2011

Re: Partially Spun Hub Vibration?

R Socey said:
Could a partially spun hub be responsible for a periotic vibration; it was only discernible at very low rpms. in foward gear?

Very low RPM as in no-wake speed?

Do you still have all the torque desired to get on plane?

Do you still attain top speed at the same RPM as before the vibration?

Fed · Jan 12, 2011

Re: Partially Spun Hub Vibration?

If it's a pulsing or very light thumping you can feel through the steering wheel then you could be trimmed in or out too far.
Idle speed is the least likely to give you prop spin in fact that's how we limp home after spinning a prop.

R Socey · Jan 12, 2011

Re: Partially Spun Hub Vibration?

Sound info guys - thanks! The rpms very low; gust engaged, with
both motors running. The torque felt fine to me, but a mechanic
who tested it said it felt tired. We weren't privy to the odd rattle
at the time - his work was on the oil system. It's probably in the lower unit. I was just curious as to the term (partially spun)
what the characteristics were, if it could be associated with my rattle. My tachs diddn't work.

Robbabob · Jan 13, 2011

Re: Partially Spun Hub Vibration?

Let us know what you find. Something out of alignment that auto-corrects itself will soon become a drastic problem.

R Socey · Jan 13, 2011

Re: Partially Spun Hub Vibration?

Yea that is what worries me. I want to pinpoint the problem,
but all I can do is ponder, and run it through you good folks
right now as the boat is stripped down. Something I forgot -
stupid me! When I turned the prop by hand, I felt what I can best decribe as a scratch - very faint periodic resistance. I
removed the prop, and turned the shaft again many times and
it felt silky smooth. That is what launched me on this subject.
I will be sure to post after the props are done, and installed what I ultimately find - thanks! It might be awhile.

emilsr · Jan 13, 2011

Re: Partially Spun Hub Vibration?

A out of balance prop or a bent "ear" can cause this. Give the prop a good visual inspection....have a pro look at it if you don't find the problem elsewhere.

I doubt it's the hub.

If you're feeling some "dragging" when spinning the prop you need to address that as well. It should spin freely without touching anything. Usually a little sanding/griding can fix this (isn't all that uncommon), but make sure a bent prop shaft isn't causing the problem before removing material on your prop.

R Socey · Jan 13, 2011

Re: Partially Spun Hub Vibration?

Thanks I'll mention that to the prop shop.

Dhadley · Jan 13, 2011

Re: Partially Spun Hub Vibration?

What motor or motors are we talking about?

R Socey · Jan 13, 2011

Re: Partially Spun Hub Vibration?

Twin 1985 Yamaha 150 etxk 2 stroke V6 standard rotation

Partially Spun Hub Vibration?

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