Broken starter bolt hole.. yup cracked.. fix?

ericp501

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May 14, 2011
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149
So the hole where the bolt goes in to hold the starter on my 4.3 mercruiser is broken.. Like split in half so I actually have a chunk of metal in my hand off the block that has half the threads for the the starter bolt in it. I'm sure I can come up with some type of fix, but I figured I'd ask if anyone knows of the "perfect" fix.
 

Don S

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Re: Broken starter bolt hole.. yup cracked.. fix?

You need a new block. There is too much pressure on that outside bolt hole on the block to ever try a weld repair on cast iron.
 

tpenfield

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Re: Broken starter bolt hole.. yup cracked.. fix?

If super glue does not work, then it may be worth having a machine shop take a look. Replacing the block for something like that would be insanely expensive.
 

joewithaboat

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Jul 3, 2011
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Re: Broken starter bolt hole.. yup cracked.. fix?

Not sure how these end up like this ??

I helped someone fix one like this before on the outer hole on a small block Chevy. We drilled the hole out bigger, ground a flat spot on the top and used a bolt down from the top and put a nut on the bottom of the starter. Was ugly as hell but worked because it didn't rely on the threads in the block that were mostly missing.

It will be rigged, but may work, and if you sell it be sure to disclose this ;)

Hope this helps.:)
 

mike165

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Apr 14, 2011
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Re: Broken starter bolt hole.. yup cracked.. fix?

This happened on my 250 L6 someone had helicoiled the outside hole before i got it,and it pulled out,drilled the hole up and thru the cast ground a high tensile bolt down works good
 

ericp501

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May 14, 2011
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Re: Broken starter bolt hole.. yup cracked.. fix?

Yea I'm sure I can come up with something. No way am I going to scrap a strong running engine and throw away all that time and money just for something like that. I'll have to take another look at it. I thought about putting in a bolt from the top but didn't think id get the clearance. I could also tap a new bolt of some type, I was even thinking about making a type of counter force rod that attaches to the block by the drain plug and pushes outward on the starter stopping it from jumping out, this is how I got it started using my dad and a crowbar. My father has been a mechanic for over 30 years and has come up with some pretty amazing fixes in the past. The boats winterized for now, but next spring I'm sure we'll put a fix on it
 

jimdonnelly50

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May 28, 2012
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Re: Broken starter bolt hole.. yup cracked.. fix?

My starter stopped engaging, I crawled down best I cold to look at how to remove starter, Looks like I have the same problem on a 1996 4.3L... The outside starter bolt hole has a chunk of the engine block broken off exposing the bolt... Don't know how long it's been like this.. Bolt doesn't look loose, starter assembly seems tight to engine.. who knows what happens when I pull the starter out...

Did you you get this fixed? how?
 

ericp501

Petty Officer 2nd Class
Joined
May 14, 2011
Messages
149
Re: Broken starter bolt hole.. yup cracked.. fix?

My starter stopped engaging, I crawled down best I cold to look at how to remove starter, Looks like I have the same problem on a 1996 4.3L... The outside starter bolt hole has a chunk of the engine block broken off exposing the bolt... Don't know how long it's been like this.. Bolt doesn't look loose, starter assembly seems tight to engine.. who knows what happens when I pull the starter out...

Did you you get this fixed? how?



I did.. I used threaded rod. If u look at my threads you'll see I started one that shows what I did
 
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