{Stus-List} Engine / Prop Shaft Alignment, Stuffing Box

Nauset Beach nausetbeach at optonline.net
Wed Jun 4 07:49:39 EDT 2008


Once again I come back to the well of knowledge:

Problem # 1: vibration when in gear.  

History:  
March, 2006:  replaced engine mounts with same OEM mounts [Yanmar],  aligned engine / shaft
2006 season:  little vibration during use, though more than prior season
2007 season:  Vibration worsens - am guessing due to compression of new mounts
April, 2008:  replace 3 yo cutless bearing, installed gore-tex packing in stuffing box [Problem #2 below]
vibration slightly less but intolerable, and probably damaging to something

Prop: geared, folding Flex-o-Fold.  cleaned and greased April, 2008.

Checked alignment last night: slight gap at bottom of coupling faces
Lowered front two mounts - gap closed.  3/1000" feeler guage is close to equally tight all round coupling.

Port forward mount is closer to the top of the threads on the post than the other 3.  Raised question:  Is this creating "torque" on the engine itself with unequal amounts of weight on each mount?  How does one "equalize" the percentage of weight on the four mounts?  Could this be causing the vibration?  Any suggestions as to what else to check?  Stainless shaft is slightly scored presumably due to delay in packing replacement 8 years ago. 

Problem # 2:  no water through stuffing box.

April, 2008: Replaced PTFE packing with the Gore-tex packing - boat was on the hard.
Tightened stuffing box - possibly overtightened - as was not on board at launch and did not want water leaking in prior to my return.
After launch, loosened stuffing box and cannot get water through the packing.  Water does run along the threads of the stuffing box when I loosen the packing nut but not out along the shaft. When the nut is tightened to stop the flow out the threads, the shaft gets hot.

Conclusion:  Am guessing I need to replace the packing again as it probably was packed too tightly in the packing nut and is now preventing water to flow.  With the boat in the water, was hoping to avoid that adventure.  Thoughts?

Any suggestions on either situation are appreciated.

Thanks,
Brian
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