Mercury wear pads missing cause of vibration?

woodguy81

Petty Officer 3rd Class
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Mar 30, 2019
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98
So for the moment I’ve got everything working as it should on my boat. Merc 5.0 mpi with an alpha one gen 2 behind it. My question is that at low rpm in gear the boat has a slight vibration to it that goes away with a little more rpm. The drive is a new sei marine unit but I’m pretty sure it did it with the old unit before I replaced it as well. Tried a couple props too. Currently running a revolution 4 in a 15 pitch. Looking over everything I noticed the plastic shins are not and probably never were there since I owned the boat. Could these missing be cause for concern or a reason for the vibration? Also. Looking online I can’t tell if they are the same for the bravo and alpha units. Can someone help me find the correct ones?
 

tank1949

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Joined
Apr 4, 2013
Messages
1,894
So for the moment I’ve got everything working as it should on my boat. Merc 5.0 mpi with an alpha one gen 2 behind it. My question is that at low rpm in gear the boat has a slight vibration to it that goes away with a little more rpm. The drive is a new sei marine unit but I’m pretty sure it did it with the old unit before I replaced it as well. Tried a couple props too. Currently running a revolution 4 in a 15 pitch. Looking over everything I noticed the plastic shins are not and probably never were there since I owned the boat. Could these missing be cause for concern or a reason for the vibration? Also. Looking online I can’t tell if they are the same for the bravo and alpha units. Can someone help me find the correct ones?
I suspect bad plug or wire somewhere. Pull wires at low RPMs and see if motor noise/rpm changes.
 

woodguy81

Petty Officer 3rd Class
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Mar 30, 2019
Messages
98
I suspect bad plug or wire somewhere. Pull wires at low RPMs and see if motor noise/rpm changes.
The vibration is only when it’s in gear. Plugs and wires are all pretty new as well. Motor sounds good. I’ll check them anyway though.
 

tank1949

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The vibration is only when it’s in gear. Plugs and wires are all pretty new as well. Motor sounds good. I’ll check them anyway though.
In gear is when you have a load on motor and LOW rpms. MCs have a very good motor anchoring mounts, not like a car's. I have been fooled by bad wires or plugs too on a boat motor.
 

Bondo

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What are wear pads?????????? Maybe I am referring to something else???
Ayuh,.... The alpha, gen.IIs have plastic pads where the drive meets the gimbel ring,....
Donno if that'll cause a vibration, but I'd make sure they are replaced, Pronto,....
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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What are wear pads?????????? Maybe I am referring to something else???
if the motor is severely out of alignment, you can get a vibration. hence the reason I asked when the motor was last aligned
 

tank1949

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Apr 4, 2013
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Ayuh,.... The alpha, gen.IIs have plastic pads where the drive meets the gimbel ring,....
Donno if that'll cause a vibration, but I'd make sure they are replaced, Pronto,....
I had a gen 2 but don't recall seeing them. Mine didn't vibrate. Hum...
 

tank1949

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if the motor is severely out of alignment, you can get a vibration. hence the reason I asked when the motor was last aligned
I now remember those but I thought that they were just shims to make a better alignment or a tighter fit...
 

woodguy81

Petty Officer 3rd Class
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Mar 30, 2019
Messages
98
Sorry. Been away. Alignment was checked last time the drive was off with the proper tool. Slid in and out perfectly. I have so far bought an almost complete set of tools to work on this boat. Lol.
 
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