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Old 08-03-2013, 07:29 PM
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d2jp d2jp is offline
MC Fanatic
Join Date: Jun 2011
Boat: 1992 PS 205-351w,285HO
Location: Smith Mountain Lake, VA
Posts: 815
Originally Posted by XavierSPL View Post
So a pictureless update for now and more confusion regarding this vibration..

I decided to drop it off at the shop after last weekend to have everything measured up to find the source of the vibration and they cannot find any explanation. I'm getting conflicting info between a couple sources at this point:

The shop measured the coupling gap and shaft, found no gap variances at the coupler and less than .0015 at multiple points on the shaft. The strut and cutlass bearing have no play whatsoever either. I felt at that point that it must be the prop but the mechanics at the shop felt that it wasn't damaged enough to cause the kind of vibration I'm describing.
I decided to have the prop done regardless since it does have damage so I brought it down to H&H (seem to be the most reputable in this part of New England) and dropped it off. When they looked at it they said it was in terrible shape and def needed to be done for what you can see in the pics. They said they agreed that the damage to the fins may not have been enough to cause the vibration but they pointed out that there was some scoring/wear in the bore of the prop that shows it hadn't been seated properly on the shaft whenever last installed and that that was what was causing the vibration under load.. The said it should be installed with some type of sandy-grit stuff?? I subsequently stopped by the shop again and told them what they'd said and the mechanics disagreed and said they had to really fight to get the prop off the shaft (more so than normal) and didn't see anyway it could've had any play..
Oh well, I'm out of ideas for now - couple more days and a little over $200 for the prop repair and we'll see what happens next weekend when I get her back in the water.
This week coming the shaft log will be getting new glass and I'm going to try and order up a new cutlass bearing for the strut since it's all apart. (planning on XPS, any thoughts?)
I just went through a similar process - leak around the shaft log and decided to replace the cutlass bearings with XPC while I was doing it. My boat would take on water while docked. After fixing this leak it's extrememly dry!

I also seated my prop using the MC suggested method per the owner's manual that came with our boats, which is using valve grinding compound on the shaft to eliminate any high spots and ensure a contact area of something like 70%. Here's a link:

I'd guess the vibration is the prop, either damage or...possibly if it's not seated properly and has rotated some on the shaft to where it's hard to remove...maybe it's also slightly 'out of balance'? Have no idea on this last statement, just a wild a$$ guess
1992 ProSport 205
(Former) 1989 ProStar 190 Power Slot
Smith Mountain Lake, VA
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