Mercruiser 4.3L starter removal

[v1_0]

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]

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]

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]

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]

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]

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]

Correct bolt is a long 3/8s - with a ½" (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
½" 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]

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]

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]

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]

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