Another Leaking Transom Issue

[tank1949]

A rotten transom will still "feel" solid, you have to know what you're looking for to spot it. One of the tell tale signs of a rotten transom is that someone will put a copious amount of silicon around the drive in an effort to band-aid the leak.

Another way to check for a bad transom is to tie the bow to a dock and reverse a little bit and see if the flow of water increases into the bilge. Reversing will cause the transom to flex in such a way that if it's rotted, more water will pour in.

If you have transducer or trim tabs, remove screws and pray no water comes out. If you see brown ooz under motor, you will have to pull motor and rebuild transsome. That sucks! Been there! Another way to test, if you haven't already done this is to fill boat with water (bow up) and see if water comes out around gimbal housin. If so, you are screwed too! Good luck!

 

[ScottieScott]

If you have transducer or trim tabs, remove screws and pray no water comes out. If you see brown ooz under motor, you will have to pull motor and rebuild transsome. That sucks! Been there! Another way to test, if you haven't already done this is to fill boat with water (bow up) and see if water comes out around gimbal housin. If so, you are screwed too! Good luck!

I have a depth finder attached to the transom, as well as the speedometer sensor wheel. Will check those attachments as well.....good call.....don't have trim tabs tho.

Overall I have a bunch of things to still check....transom, trim hose manifold, depth finder/speed indicator attachments.....I hope it isn't the transom, but if it is, like I said, there will be another 'band-aid' put on it by re-sealing the transom assembly with 3M 4200 FC. I will try to loosen the entire assembly and get a decent amount between the assembly and transom.

Thanks all for your help.

 

[Bondo]

I have a depth finder attached to the transom, as well as the speedometer sensor wheel. Will check those attachments as well.....good call.....don't have trim tabs tho.

Overall I have a bunch of things to still check....transom, trim hose manifold, depth finder/speed indicator attachments.....I hope it isn't the transom, but if it is, like I said, there will be another 'band-aid' put on it by re-sealing the transom assembly with 3M 4200 FC. I will try to loosen the entire assembly and get a decent amount between the assembly and transom.

Thanks all for your help.

Ayuh,.... There ain't no Bandaid for a rotten transom,... To loosen the nuts, ya gotta pull the drive, 'n motor 1st,...
At that point, Replace the rotten wood,....

 

[ScottieScott]

Ayuh,.... There ain't no Bandaid for a rotten transom,... To loosen the nuts, ya gotta pull the drive, 'n motor 1st,...
At that point, Replace the rotten wood,....

I am sure you are correct about no Band-Aid. So let me ask then....I have seen transom repair from the outside of the boat, where the outer shell is cut off and saved, then the rotten wood is removed and replaced with new plywood coated in epoxy, then the outer shell is re-attached with epoxy and re-gel coated. This was on a boat that took an outboard.

So the question is this. Could I use the same process to get to the rotted wood, if that truly is the case here, and not have to remove the motor, just the outdrive and transom assembly?

 

[Scott Danforth]

it will be so much easier, cheaper, and faster to pull the motor and do it right from the inside. no one cares that the tabbing isnt perfect on the inside (you cant see it), however it will be so much more work to properly repair cutting the outer skin off.

it only takes 1-2 hours to pull the drive, motor, and transom shield.

 

[Bondo]

I am sure you are correct about no Band-Aid. So let me ask then....I have seen transom repair from the outside of the boat, where the outer shell is cut off and saved, then the rotten wood is removed and replaced with new plywood coated in epoxy, then the outer shell is re-attached with epoxy and re-gel coated. This was on a boat that took an outboard.

So the question is this. Could I use the same process to get to the rotted wood, if that truly is the case here, and not have to remove the motor, just the outdrive and transom assembly?

Ayuh,.... The rear motor mounts attach to the inner transom plate, ya can't pull the transom assembly with the motor sittin' on it,...

Ya pull the drive 1st, then the motor, then the transom assembly,...
Replace the rotten wood, from Inside the hull, then reassemble the opposite of removal,...
Not fixin' it causes motor/ gimbal/ drive alignment issues, that'll ruin the coupler,... which requires pullin' the motor to replace,...

 

[ScottieScott]

it will be so much easier, cheaper, and faster to pull the motor and do it right from the inside. no one cares that the tabbing isnt perfect on the inside (you cant see it), however it will be so much more work to properly repair cutting the outer skin off.

it only takes 1-2 hours to pull the drive, motor, and transom shield.

Well I don't want to get into this over my head and I don't really have the tools to pull the motor, so I am not sure what I would be in for.

Are the steps to pulling the motor these? Removing the outdrive, disconnecting the remote cables, battery cables, and fuel lines? I suppose there are a bunch of wires to the dashboard for gauges and ignition that need to be detached. What else am I missing?

When you say transom shield, I am not sure what that is. The inside of my transom appears to be the 'sprayed in' or 'exposed' fiberglass. I would need to cut that out, but I don't think that there is anything in there that is 'bolt on' if you will.

I am good at taking things apart, but re-assembly is another story.

 

[Fishermark]

Pulling the engine is easy - relatively speaking. Once you pull the engine, here's what you will see (basically):

This is what the inner transom shield looks like (basically):

 

[JASinIL2006]

Pulling the engine isn't really that hard. The key is to take lots of pics and label EVERY wire you disconnect. Most of the disconnections are done via large plugs where a number of wires are bundled. It's not that bad. I've never worked on engines before and I was able to get mine out to replace the transom. Lots of folks here who can help you through it...

I think the "transom shield" that Scott Danforth refers to is the inner transom plate. It's a fixture that is thru-bolted to the gimbal assembly (on the outside of the transom) and it serves as the rear motor mounts. It's a heavy metal plant that surrounds the keyhole.

Some people also use "transom shield" to refer to the plywood plate that is fiberglassed inside the hull to the transom. In this usage, the transom shield would generally be partially rotten, which is what leads to this sort of project. (Some people also call this the 'transom core'.) This plate/core/shield provides the structural integrity to the transom. The stuff you see on the inside of the boat ("The inside of my transom appears to be the 'sprayed in' or 'exposed' fiberglass") is the fiberglass cloth that covers your transom core. The core is 'glued' into the hull (usually using thickened resin called Peanut Butter), then "tabbed" to the hull with strips of resin-soaked fiberglass, and then covered with a fiberglass cloth or mat, to make it stronger and protect it from water.

Hope that helps!

Jim

 

[ScottieScott]

Looks like a bit of a nightmare too me (someone who has never done this before).

I would need to rent an engine puller, but that is probably all. Like I mentioned earlier, I can get things apart, but this looks tough to put back together.


I need to double check the boat for the extent of the damage before I get ahead of myself, it is in storage at the lake we go to a few hours away. If the transom truly needs to be rebuilt, then I have a decision to make.....Do I make the effort to repair a 28 year old boat transom, where other things may continue to fall apart, or do I make the repairs and hold onto the boat for a few more years?

 

[JASinIL2006]

Also, read some of the restoration threads thoroughly (mine is listed in my signature). Many of us wound up having to do this with our very first boat. It seems like a pretty daunting job, but if you break it down into smaller chunks (e.g., pulling outdrive; disconnecting engine; pulling engine from boat; removing rotted transom, etc.), it's really not so bad. A lot of work, yes. But it's possible if you're reasonably handy and have someplace to work.

 

[ScottieScott]

Well I would never try it if it weren't for this forum......and I am getting the courage to try. The boat is only a 19.5' open bow, but it is in great cosmetic shape (with the exception of this transom issue, which is structural anyway). I'd like to get it into great shape for a few more seasons. I guess it all depends on what the wife says. Something like this would get me out of the house for quite a while - lol.

So the next question would be - how heavy is the Mercruiser 170 motor? If I actually do this, I can get an electric motor hoist from Harbor Freight for about $150. I would need to reinforce my rafters somehow though to be able to support the weight.

 

[Bondo]

Well I would never try it if it weren't for this forum......and I am getting the courage to try. The boat is only a 19.5' open bow, but it is in great cosmetic shape (with the exception of this transom issue, which is structural anyway). I'd like to get it into great shape for a few more seasons. I guess it all depends on what the wife says. Something like this would get me out of the house for quite a while - lol.

So the next question would be - how heavy is the Mercruiser 170 motor? If I actually do this, I can get an electric motor hoist from Harbor Freight for about $150. I would need to reinforce my rafters somehow though to be able to support the weight.

Ayuh,..... If, the transom is rotten, ya might wanta cut yer losses, 'n part out that 470 to somebody, then take the money, 'n go buy Another 19.5" open-bow, with a 4.3l, or 5.7l,...

 

[ScottieScott]

Ayuh,..... If, the transom is rotten, ya might wanta cut yer losses, 'n part out that 470 to somebody, then take the money, 'n go buy Another 19.5" open-bow, with a 4.3l, or 5.7l,...

Certainly an idea, but probably couldn't get enough to make it worth our while. If we end up scrapping this one, it will be for a bigger boat. For a family of 5 this one gets pretty crowded. No room for any of the kids friends either. The transom might be an interesting challenge....but the reality is that I am not sure how bad it actually is yet.

Are you suggesting cutting my losses because of this engine?

 

[Bondo]

Certainly an idea, but probably couldn't get enough to make it worth our while. If we end up scrapping this one, it will be for a bigger boat. For a family of 5 this one gets pretty crowded. No room for any of the kids friends either. The transom might be an interesting challenge....but the reality is that I am not sure how bad it actually is yet.

Are you suggesting cutting my losses because of this engine?

Ayuh,.... 470s are gettin' Rare,.... Runnin' 470s even Rarer,.... It's the guys with Twin 470s that'll pay the most for 'em,...
They can't go to a V-motor, so it's a 470, or a I-6 Chevy, or refit the hull with wider drives,...

 

[ScottieScott]

Ayuh,.... 470s are gettin' Rare,.... Runnin' 470s even Rarer,.... It's the guys with Twin 470s that'll pay the most for 'em,...
They can't go to a V-motor, so it's a 470, or a I-6 Chevy, or refit the hull with wider drives,...

Ok then, to change the subject of this thread just a bit......what would you consider the most reliable I/o motor? Thinking of the upgrade to a larger boat, a 24foot deck boat hopefully.....what type of engine should I be looking for? I would rather be overpowered than underpowered.

 

[Bondo]

Ok then, to change the subject of this thread just a bit......what would you consider the most reliable I/o motor? Thinking of the upgrade to a larger boat, a 24foot deck boat hopefully.....what type of engine should I be looking for? I would rather be overpowered than underpowered.

Ayuh,.... For a 24'er, A 350 Chevy oughta do the job Just Fine,.... If ya wanta be Overpowered, go with a Big block Chevy,....
For a boat the size of yer's, a 4.3l,.....

 

[ScottieScott]

Ayuh,.... For a 24'er, A 350 Chevy oughta do the job Just Fine,.... If ya wanta be Overpowered, go with a Big block Chevy,....
For a boat the size of yer's, a 4.3l,.....

Thanks.....the next boat we buy will for sure be newer, and I know what to look for. This boat is/has been a good boat for us - a starter boat so to speak.

 

[500dollar744ti]

Ayuh,.... 470s are gettin' Rare,.... Runnin' 470s even Rarer,.... It's the guys with Twin 470s that'll pay the most for 'em,...
They can't go to a V-motor, so it's a 470, or a I-6 Chevy, or refit the hull with wider drives,...

They can't fit two 3.0 liter engines?

 

[ScottieScott]

They can't fit two 3.0 liter engines?

I have actually heard that the 3.0L is probably the only option other than a rebuilt 470 with twins - but they are way underpowered. If you don't have twins, a mechanic told me that a 4.3L would fit with mods, but you would need to ensure the gear ratio of the drive is correct.

For us, my 3.7L runs great, and has good compression. A replacement motor if this one were to shoot craps is more reasonable than a new boat.

The transom repair is my therapy, kind of like golf to others. It gets me out of the house, makes my mind focus on solutions, and keeps me busy.

So other than buying the boat we actually want for probably 10x what we paid for this one, I will most likely repair this one and keep it for a while. If I totally mess it up, I sell the motor and outdrive, then sell the boat and trailer for pennies on the dollar.

I know some of you are just shaking your head at this, but we like the boat, and a fully rebuilt 470 is only a few thousand dollars.

At this point, as mentioned before, I am not 100% sure the transom is rotten - but I suspect it is.

Thank you to all for helping me understand the options I have on this project/repair, and what to expect when getting into them.