Repower or throw in the towel?

[smokeonthewater]

Re: Repower or throw in the towel?

no the outdive (on this boat) does NOT bolt to the engine... the outdrive bolts to the transom assembly which hangs from the transom and the rear motor mounts set on the transom assembly and do not take ANY of the torque that is applied to the boat by propeller thrust....

A "wet" transom is not particularly dangerous but it DOES lead to a future problem that is VERY dangerous which is a rotten or de-laminated or otherwise weak transom....

If the transom is solid and sound you can go a while... if it is rotten it's done.

 

[matt167]

Re: Repower or throw in the towel?

With an I/O if the transom seal is not leaking due to a rotten/ flexing transom, your probably 'ok'. The transom does not see direct force like an outboard. It still can't be total mush. You can probably go in thru a ski locker and check your stringers, they don't have to be perfect to be safe, but they can't be mush either.

If the transom is 'ok' and the stringers are 'ok', than the deck is probably good enough

 

[smokeonthewater]

Re: Repower or throw in the towel?

With an I/O if the transom seal is not leaking due to a rotten/ flexing transom, your probably 'ok'. The transom does not see direct force like an outboard. It still can't be total mush. You can probably go in thru a ski locker and check your stringers, they don't have to be perfect to be safe, but they can't be mush either.

If the transom is 'ok' and the stringers are 'ok', than the deck is probably good enough

YES it absolutely does

 

[geneseo1911]

Re: Repower or throw in the towel?

Let's back up a little. Are there ANY stress cracks radiating from the keyhole on the transom? On my boat, which I would descibe as having relatively minor rot, there were a couple stress cracks, so I would say that is your early warning system.

Also, the panel over the fuel tank comes up quite easily with 8 screws and gives better access to the stringers to do some poking around.

Also, not here to argue, but let me make one little point. If you look at my build thread linked above, there is a nice shot of the engine bay after I rebuilt it. I put it back basically the same way Cobalt did, but I made one modification.....I extended the main stringers to the transom. The factory build stops the stringers right at the motor mounts, and just used 2 sheets of CSM from that point (just flat) to the transom. There are short "stringers" on the floor which carry the motor mounts and transfer force (I assume) to the main stringers. My point is that it looks like Cobalt expected a significant percentage (25%? 50%? who knows) of the force to transfer through the engine to the stringers. The transom layup was 2" thick about 20" wide, 1" thick to about 2-3" inside the stringers, and 1/4" (encapsulated both sides of course) to the gunwales.

NOW, let me also say that no leak is acceptable nor is any amount of rot (IMHO, IANAL, YMMV). In order for the force to transfer to the engine, the transom must be solid. There is no direct connection between the outdrive and the engine except the transom wood, and the 8 bolts, but they are trying to compress the wood and would be loose if the transom were compromised. So basically everything I said above can and should be ignored because it is all academic.

 

[sailor26]

Re: Repower or throw in the towel?

You all have provided me some good info to work on. This weekend I will take the tarp off and do some investigative work and let you know what I find.
Geneseo, the transom is 2" thick about 10" either side of center? I followed your link but only saw a couple shots of your project, showing the motor out-inner transom stripped-stringers out. You have other shots?

 

[smokeonthewater]

Re: Repower or throw in the towel?

the stringers are there to support the bottom of the boat... yes tying to the transom supports the bottom of the transom but the engine does not transfer the force that the transom sees to the stringers... the bulk of the force put on the transom is a rotational force that seeks to rip the part at the top of the drive away from the boat in forward gear or pull the bottom away in reverse... once the wood is gone it takes surprisingly little force to do rip the boat apart.

 

[geneseo1911]

Re: Repower or throw in the towel?

SOTW-That picture is a great reminder of how important transom integrity is. I still don't understand how that boat didn't sink. And it was only a 4-banger. Now consider double the horsepower and torque. I was just making a couple observations on how the boat was originally built.

S26- Check out the 3rd picture in the first post, it shows the extent of my rot and the original build. Posts 9 & 10 have pictures of what I put back in. I did make the middle sheet a bit wider than factory as well; it originally stopped just inside of the stringers and I extended it out to tie everything together.

 

[smokeonthewater]

Re: Repower or throw in the towel?

my BET is that it did sink.... It's on my local craigs list now for $1300... they CLAIM all it needs is "a little glass work on the transom".