No clearance between starter bolt and flywheel housing on 4.3L 175hp

DanIsCool

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Jun 30, 2022
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Hello, I’m trying to replace the starter on my 4.3L v6 mercruiser motor on my 1987 Searay Sundancer. As far as I know the motors are original from 1987. I’m unable to get a socket on the bolt closest to the flywheel housing since there’s not enough clearance between the bolt and the housing for a socket to get on. I’ve tried grinding one down as thin as I can and still no dice, there’s just not enough room. Has anyone ever experienced this? Could it be corrosion? Does anyone have any ideas? It is extremely stuck, and I haven’t had any luck with an open ended wrench of any type. Serial number is B649370 if that helps explain anything.
 
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dubs283

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Jul 27, 2005
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A flare wrench may work, otherwise you may have to remove the inspection plate from the flywheel cover
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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pull the inspection cover

or just force it on (deforming the inspection cover)
 

Chris1956

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Mar 25, 2004
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If memory serves, didn't the starter bolts on the 4.3l motors have special starter bolts with "tall" hex heads, to clear the flywheel housing?
 

Bondo

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Ayuh,..... option 1 is to remove the tin or plastic cover, whichever you have,.... there's 4 small bolts holding it on,....
'n yes to Chris,.... If you can get the starter off, Merc offers starter bolts with extended 1/2" heads, rather than the usual 9/16" heads,.....
 

Lou C

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Nov 10, 2002
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The ARCO starter I put in my boat a few years ago had different bolts with a taller hex, made it easier to install, in addition to it being smaller and lighter by a lot!
 

DanIsCool

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Jun 30, 2022
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Thank you all for the advice - I’m new to the forum and figured I’d get an email or something when I got a response which is why I didn’t check until now to see if anyone replied.

I thought about removing the inspection cover but some of those bolts are a little tricky to get to as well. The bolts on there were the taller 9/16” heads. The new starter I got is a lot smaller and uses 1/2” bolts. I ended up getting the bolt off, we had to grind down a 9/16” socket super thin. Concerning my thin, but it worked! The new smaller bolts went on with a normal socket so that’s nice. Thanks again everyone for the advice, it’s good to know for if the next engine gives me trouble…
 
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