Mercruiser 4.3L starter removal

v1_0

Chief Petty Officer
Joined
Aug 27, 2007
Messages
575
Hello,

I'm trying to pull the starter for a 1999 Mercruiser 4.3L: I can get to one of the bolts easy enough, but the other one is so close to the flywheel shroud that I can't get a socket around it. I've tried to use a wrench, but the bolt is in too tight and the wrench just slips off. (I've hit it with WD40, but that didn't loosen it enough).

Is there a way of getting to the bolt without needing to pull the engine?

Thanks,
-V
 

Haut Medoc

Supreme Mariner
Joined
Jun 29, 2004
Messages
10,645
Re: Mercruiser 4.3L starter removal

Use some Kroil or pb blaster on it.....
WD40 is not a lubricant.....
Can you get a vice grips on it?......
You may need an exceptionally thin walled socket....
I'm sure someone will have some more precise advice on this, so stick around.....
Welcome to iboats, btw....:)
 

superpop

Master Chief Petty Officer
Joined
Mar 5, 2006
Messages
869
Re: Mercruiser 4.3L starter removal

I know exactly what you are talking about. have you tried both a 12 point and 6 point socket. I think the 6 point socket will barely fit. it is tight though and you may have to bang the socket on with a hammer. That is what I did.
 

Daddy5295

Seaman
Joined
Jul 31, 2007
Messages
56
Re: Mercruiser 4.3L starter removal

I used a 6 pt wrench to get mine off, 12 pt will slip worse on a tight bolt. Also make sure whether it is metric or standard, and use the tighter fitting one. I have both standard and metric on my motor? What a pain.
 

Gary H NC

Fleet Admiral
Joined
Dec 1, 2005
Messages
8,972
Re: Mercruiser 4.3L starter removal

The boat i used to have with the 4.3 was a pain to get to one starter bolt.
I ended up pulling the lag bolts loose on the engine mounts and lifted the engine about 3 or 4 inches to get to it. Hope you don't have to go that route but its possible.
 

searay3

Senior Chief Petty Officer
Joined
Apr 7, 2005
Messages
655
Re: Mercruiser 4.3L starter removal

Get a cheap 6 pt wally world socket and carefully grind the outside down until it's thin enough to get on the bolt. I had a concern that the strength would be lost on the thin wall. It has worked numerous times.
 

elpaso

Petty Officer 1st Class
Joined
Jun 27, 2003
Messages
264
Re: Mercruiser 4.3L starter removal

Correct bolt is a long 3/8s - with a ?" (reduced) head that
allows you to get a socket on it , without hitting flywheel
cover.
But many times the bolt from factory takes a 9/16 socket,
and the bolt flange is binding on the cover. And you can not
get a socket on.
If you take the first 3 short 1/4" bolts out of the flywheel
cover, to give it some play - wedge a flat blade screwdriver
between cover and engine block - a long socket will fit.
If not grind tip of socket down - and hit screwdriver with
very large hammer. If socket fits but bolt will not move heat the block
where the bolt threads are located. If still no go, cut a vertical
grove the lenght of bolt in starter housing with Dremel tool,
relives pressure from rust. If this dosn't work, sell boat.

When installing new starter make sure you use the reduced
?" head with a lot of antsize.
You may want to grind down flange on bolt for more
clearance ?
Install new style starter - much lighter-smaller-more power.
 

farmboy

Seaman Apprentice
Joined
Oct 11, 2006
Messages
33
Re: Mercruiser 4.3L starter removal

I really hate it when someone suggests using a "hammer" to do a socket or wrench job. Grind, file or hammer the tool to fit the machine; use that ball peen carefully on the casting unless you really want to break it.
 

wire2

Lieutenant Commander
Joined
Jun 25, 2007
Messages
1,584
Re: Mercruiser 4.3L starter removal

A replacement 3/8" bolt with a 1/2" hex head may be difficult to find.
I'd suggest going with an Allen head bolt when you do get it off.
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Mercruiser 4.3L starter removal

A replacement 3/8" bolt with a 1/2" hex head may be difficult to find.
I'd suggest going with an Allen head bolt when you do get it off.

Merc sells them. Only the old style bolts had the 9/16 head. All the new ones are 1/2"
Merc used to add a pack of new bolts in each starter. But stopped that practice about 2 years ago.
 

v1_0

Chief Petty Officer
Joined
Aug 27, 2007
Messages
575
Re: Mercruiser 4.3L starter removal

Got it off!

Thanks for all your help. The method I ended up using was to remove the flywheel shroud entirely - then I could get the socket on the bolt. As an added bonus, the shroud was rusted through in a few places so its a good time to replace it...

-V
 
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