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Motor Mount Lag Bolt Fun

makomark

makomark

Silver Medal Contributor
"I checked my boat last night,

"I checked my boat last night, before the big blow, and had some extra time so caught up on some maintenace actions. Found the forward outboard motor mount, on the port engine loose. upon more detailed inspection found it was broken off, flush with the stringer.

We had a few "pop" over the years but there was always enough of a stub portruding to grab it with the vicegrips. Guess I've run out of luck in that department.

Any suggestions from the "been there, done that" community, for the least labor intensive approach to extracting the remnants?"
 
Can you drill another hole in

Can you drill another hole in the metal part and use another lag bolt?

Jeff
 
Maybe...trick is get the pilot

Maybe...trick is get the pilot hole started in the center. and then keeping it there. I know I've got the better part of 4" of that beast down in the stringer.

Thanks for the suggestion.
 
"Mark,

You just freaked me

"Mark,

You just freaked me out... Now I've gotta go check my mounts. That job has just gotta be a PITA. Previous owners mounted all kinds of interfering parts, tanks or heaters in those outboard spaces. I hate to think about those prospects"
 
"Al:

Sorry to scare you...b

"Al:

Sorry to scare you...better at the dock than offshore though.

This is the first bolt to break since the major overhaul so you can figure you got at least ten years if you did it right.

When we first got this boat, we were changing them pretty regularly, unfortunately. After that season, post haulout, read all the documentation. Turned out the factory messed up when doing the installation...they used 3/8" diameter where Crusader was pretty clear about 1/2" diameter.

I just hope the nylon hasn't become frozen due to rust in the metal ring...so far, the couple that have broken haven't been a problem....BTW, if they say use a 3/8" dowel thru opposing holes, DON'T let someone help by putting a screwdriver thru only one. It seems to bust them every time. Yes, I got to break one of them though."
 
"I would eliminate the problem

"I would eliminate the problem permanently by thru-bolting a 10" length of H.D. 4" angle to sides of the stringers with the angle overhanging the top of the stringer. The top of the angle will accept the isolator. This will require notching the stringer so you can recess the bracket. You do not want to change the plane of the isolator. You can now use 1/2" machine bolts to bolt the isolator to the top of the angle bracket. I never cared for lag bolted engines and this will give you a much better, more secure and permanent installation."
 
"Yeah, I second the thru-bolt

"Yeah, I second the thru-bolt idea. Mine use 1/2" SS with locknuts on the far side. Also, using aluminum angle thru bolted to the stringer itself. This won't be possible on every install, but if possible, definately do it. That is one area I don't have to worry about."
 
"Rick:

Sounds like a much b

"Rick:

Sounds like a much better method...a couple of clarifying questions, when you can:

* Preferred material and thickness for the angle?

* When you say 'notch the stringer' do you mean to cut off the thickness to keep the height of the mounting pad the same as it is?

* Tap the angle? Use USS or SAE threads?

thanks mark"
 
"1/4" minimum, 3/8" is

"1/4" minimum, 3/8" is overkill, galvanized if possible.

Yes, notch the top of the stringer so you can mount the angle low enough to keep the isolator at the original height. This may not be necessary, depending on how much adjustment you have left in your mounts.

I would drill the brackets and thru-bolt them with stainless hardware rather than tap them. That way if you have a problem with a bolt, down the road, you can simply cut it off and replace it rather than having to deal with it being threaded into the mounting bracket. SAE threads are fine but use nyloc nuts and/or lockwashers.

Be sure to realign the motor when you're done.

Good luck,
Rick"
 
"When I asked "Tap the ang

"When I asked "Tap the angle", I was asking about the vertical 1/2" bolt to retain the motor mount.

When it comes time to do it, I'll thrubolt the horizontal ones retaining the brackets to the stringers.

Funny you mention alignment....I was checking that, along with the stuffing boxes, when I found that side's shaft was hard to turn, beyond the normal inertia that the 1.5" shafts have. Removed the coupler bolts and the coupler on that side didn't separate easily. Tapped it with the hammer to open it a bit and inserted the feeler gauge. a 020 went in in one side and didn't want to go in the opposite side. tried a 010 in the tight side and it didn't want to go. Knew there was an issue so started looking for what moved and how.

thanks again to all for the inputs."
 
Fiberglass boat? If you do wh

Fiberglass boat? If you do what Rick says--and he's spot on!--be sure to seal up any exposed interior areas with epoxy. This includes where the thru bolts will go through the stringers. Omit this step and you'll be immensely sorry!

Jeff
 
"Jeff,

That as you know...I

"Jeff,

That as you know...IS and understatement. A previous owner added rod holders to the gunwales however many years ago. When we got the boat, I re-did 24' of balsa and epoxy about 8 " wide !

I checked my mounts and when the 454's were put in, they actually used 1/4" angle iron. Whew!"
 
"Al:

How did they secure yo

"Al:

How did they secure your mounts to the angle iron?

guess I do have a bit of luck; except for the oak pads where the mounts go, my stringers are hollow fiberglass"
 
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