Prop shaft runout

[roda]

On my '05 MC197 I have had some vibration that seems to be getting worse over time. It all started after a turtle strike. I had the prop (stock 4 blade) re-conditioned by OJ. Still had a slight vibration and found that the strut did not seem to be centered. Had MC dealer replace strut and now the shaft lines up but the runout when checked with a dial indicator is between .008 (near trans) and .013 (near shaft seal). My neighbors identical boat is .005 at most. I put his prop (identical) on and almost all of the vibration went away so I am going to buy a new Acme 3 blade.

 

Should I also try to improve the shaft runout? What is within spec? Is it possible to get it to .001 or less?

 

Thanks

[east tx skier]

If I recall, run out is supposed to be 0.002".

[boarditup]

You are fine on run-out. About 20% of the time reconditioned props vibrate. Even though they may spec out, the differences in metal tension make on blade vibrate differently than the others - just enough harmonic that everything vibrates.

 

.001 will change as the temperature changes. Don't sweat it.

 

Let me know what Acme you need. I may have it on the shelf.

[roda]

boarditup:

Acme suggested: 843-13.00X12.00VL3B SPLINE .080 cup three blade nibral prop.

 

This is a '05 197 non-slot w/ MCX.

[DW]

I would shoot for runout of .003" or less. There are several sources that suggest the same.

[jackski]

I had a hit some years ago, not a bad one but a nick and small bend in one blade. Put a new prop on and still had some vibration. I had less than .002 eveywhere except on the taper itself where the prop actuall wobbled. Put a new shaft on and it was perfect.