Mercruiser 4.3 possible mis alignment

dontask

Petty Officer 2nd Class
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Apr 5, 2009
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177
I'm new to this forum and I was hoping to get some input from one of members that has Mercruiser factory training and or professional experience. My question is I bought a boat with a 4.3 ? alpha 1 drive. After getting the boat home for further in depth preventative maintenance and needed repairs I found that the engines forward two mount (left side & right side) top nuts were 1 to 2 turns from being tight. My concern and question is do I need to pull the outdrive and check for alignment? Or is there some tolerances built in? FYI I'm a mechanic for a living (35 years) I just don't work on boats for my 40 hr week. I have owned outboards all my life, just never an IO. thank you
 

APPALOOSA2

Petty Officer 1st Class
Joined
Jul 9, 2008
Messages
354
Re: Mercruiser 4.3 possible mis alignment

First I would download the manual that Don has put in "ADULTS ONLY" for your Mercruiser. This way you get the specs on tightning those mounts to the correct specs.

Yes I would go to Ebay and about $60 you can get a alignment tool. There is not a big tolerance at all for alignment. The $60 will save you a lot of money down the road, plus you can grease the ujoints with the outdrive off.
 

Bondo

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Re: Mercruiser 4.3 possible mis alignment

that the engines forward two mount (left side & right side) top nuts were 1 to 2 turns from being tight. My concern and question is do I need to pull the outdrive and check for alignment? Or is there some tolerances built in?

Ayuh,... The front mounts should be Tight, 1 nut holding the motor up,+ the other nut cinching the mount to the lower nut...
Hopefully, the mount hasn't destroyed the threads in that area of the mount from vibration...
 

dontask

Petty Officer 2nd Class
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Apr 5, 2009
Messages
177
Re: Mercruiser 4.3 possible mis alignment

Up date: No the threads were not torn up. Has any other Mercruiser owners here seen this before? Meaning nuts backing off or was it just poor assembly from Mercury (approx 160 hours on boat).
 

Don S

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Re: Mercruiser 4.3 possible mis alignment

Meaning nuts backing off or was it just poor assembly from Mercury

It wasn't Mercs fault. The boat manufacturer installed the engine and adjusted the alignment, they may have not tightened them, but then the selling dealer usually gets the boat with the drive off and has to install them. So then the alignment should be checked and the nuts checked for tighntess. It's part of the predelivery insptection.
Also, the drive should be removed and the alignment checked every 100 hours or yearly, whichever comes first. If the alignment was off, they should have been checked then.

Has any other Mercruiser owners here seen this before?
Never have understood this type question though. What's the difference if it has been seen or not, YOU have the problem not everybody else.
 
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