Inboard boat propeller shaft vibration ??

[callbay]

1989 US Marine Ski Challenger ski boat with 351 Ford engine. Hit the prop a couple of years ago on some wood in the water. Buggered up the prop but not real bad looking. Could not be driven over 1,200 rpm due to vibration.

Got a new to me prop in good condition and most of the vibration s gone but still not back to normal.

Could this be the motor and shaft need to be aligned? It's never been aligned since from the factory.

Or the packing on the shaft needs to be redone. It is original.

Or could the new/used prop be just not that great even though it looks good.

Thanks a ton!

 

[DoubleWasp]

I'd yank the prop and have it balanced first. Then go from there.

 

[Phishin]

Originally Posted By: DoubleWasp
I'd yank the prop and have it balanced first. Then go from there.


Exactly. I do this with our big brass blades on the Tiara every few years.

 

[CT8]

How is the bearing on the winding strut? Prop shaft straight? Is the packing leaking?

 

[Bobcatguy]

The better prop shops can computer balance it.

It might have been better to get a new prop. Keep the one you got as a spare.

 

[ledslinger]

Dial indicate the shaft on the taper and between the strut and shaft log.

 

[ironman_gq]

Good chance it's a bent shaft, pretty common on prop strikes.

 

[hattaresguy]

First send the prop out to be balanced properly, you would be amazed how far they are off.

Next you can check the shaft for straightness, also the alignment.

Also if the cutless bearing is worn that could cause issues and it might need replacement as well.

If the shaft is out, send it out to the prop shop they straighten those as well.