How to validate the condition of the wood inside the transom

[kungpaoshizi]

I was looking through pictures of my boat, and came across a 1983 (mine is 86) venture bass boat that had a transom torn apart and the wood core was in pretty bad shape...

I know my motor has moved a bit forwards and backwards, but of the 8 mounting bolts, the top 2 and bottom 2 are absent, so I'm thinking that is the majority of the movement. The bolts I'm referring to are motor to cmc PTT, not cmc to transom.

Though after looking at the pic, it makes me wonder is there a way to really check the condition of the transom wood under the fiberglass without tearing it apart?

If there's no obvious flexing of the transom, would it be best to just leave it? I'll be taking the motor off soon to restore the hull to optimal conditions and was thinking I might reinforce the transom a bit with a few layers of fiberglass. But I wondered if it's even something I should do, after all I have no idea the condition of the core inside the transom..

 

[smokeonthewater]

Re: How to validate the condition of the wood inside the transom

if the transom doesn't flex it's fine

if it DOES flex then adding "a few layers of fiberglass" to fix it would be about like putting on an extra t shirt to fix your broken ribs

 

[kungpaoshizi]

Re: How to validate the condition of the wood inside the transom

What kind of flex are we talking about though? How might you "test" it?
It's hard to tell if it's just the motor mount (since the guy didn't use all the bolts) or the transom too.. I mean, it looks absolutely perfect inside and out, but I'm sure that doesn't speak to the condition of the wood inside..
I'll have to post a pic of what I'm talking about, I almost wonder if it's on purpose to ALLOW the cmc PTT bracket to flex and take pressure off the transom..

 

[smokeonthewater]

Re: How to validate the condition of the wood inside the transom

the bracket flexing wouldn't take any pressure off of the transom...

first step is to fix the screwed up installation of the engine... put the rest of the bolts in tight unless you want to see your outboard's bracket bust and send the motor into the drink or worse yet into the boat at wot...

next stand on the anti vent plate (right above the prop) and bounce while a helper closely observes the transom from the side... ANY flex equals a bad transom that could rip apart at any time... NO flex meaning none at all equals a solid transom.... it's pretty much black and white like that

 

[kungpaoshizi]

Re: How to validate the condition of the wood inside the transom

What about successfully throwing the throttle into reverse as far as it goes as fast as you can?
Had to do this recently because I was drifting too close to a wing dam lol...

 

[Chris1956]

Re: How to validate the condition of the wood inside the transom

Look for cracking in the fiberglass where the hull meets the transom. That would be first sign, I would think.

 

[kungpaoshizi]

Re: How to validate the condition of the wood inside the transom

Well, I'm waiting for my phone to charge for pics... but, I went out and put the engine down and moved it with a good bit of force. I was correct, the flex I'm seeing is the bracket, so I surely didn't stand on it..

I do notice the motor mounts did put a dent in the top transom wall metal cover that's riveted to the top. I notice there is an area where water most likely gets in if it splashes over into the splash well.

So, I guess before I can get the cmc bracket reinforced like it should be with the remaining bolts (they won't screw into anything, just against the mount to stabilize the arms) I guess I might ask..

I intend to marine tex white the various scratches, and then goop coat-it the entire hull, should I even bother with taking the rivets (which look fine) out to open the boat up and replace the transom?

On another note, I did notice a screw that comes THROUGH the hull that was hidden by the trailer bunk. The only thing above it is the corner of the floor. From various pictures I've seen of similar (but not the same) designs from Venture boats, I'm thinking it might have been repair to a stringer under the corner of the floor, so I'm inclined to think that someone was in there before and that screw has been sticking through the hull hidden for the 5-7 years the PO had the boat. The PO said they replaced the carpeting, so I thought he might have screwed in a board or such under the carpet and the screw went through, but he said it's fiberglass under the carpet and he used adhesive only.

So if I'm going put the time into the hull, and since transom rot is inevitable(right?) why not just rip the entire thing apart? I know it might seem extreme, but I'm rather content with this boat, though I don't want to tear into it if it's been done since 1986, but don't wish to have the back of the boat snap off sometime...

 

[smokeonthewater]

Re: How to validate the condition of the wood inside the transom

please refer to my last post.... proceed in that order... until you can mount the engine securely to the tilt unit it is not SAFELY usable

 

[Watermann]

Re: How to validate the condition of the wood inside the transom

Hi Kung pao,

This is how I would "validate" if the transom wood is needing replaced. Just go pull off the end caps and then the transom cap so you can take a look at the transom wood. Take a look under the splashwell at the wood and note it's color and condition. Take less time than what you've spent here so far trying to avoid it. I have a CMC unit and every SS bolt and nyloc nut is where they should be and squeak tight. Man don't take any chances, if your here worrying about it then after checking into it you'll have piece of mind one way or the other.

 

[Part-time]

Re: How to validate the condition of the wood inside the transom

I use a 1/4" drill bit. Wrap tape around the bit about 1"-1 1/4" from the tip to not go too deep.
I drill holes on the inside of the transom at different locations and see if I get dry wood shavings or beaver puke!
If all is dry, I just fill the holes with a good marine sealant.

 

[kungpaoshizi]

Re: How to validate the condition of the wood inside the transom

Thanks guys, I'll have to pop the cap on the transom and drill a few holes as I'll have to take the motor off to get bolts into the top mount points..
Here's what I'm talking about though, the top 2 and bottom 2 bolt holes are empty :|

 

[snowman48047]

Re: How to validate the condition of the wood inside the transom

Another case of long shaft motor on a short transom boat and a PO trying to slap something together.... If there has been a screw thru the hull for 5-7 years you... are in a world of hurt.

 

[smokeonthewater]

Re: How to validate the condition of the wood inside the transom

WOW!

stop there... you either need a jack plate or preferably a different motor..... That is SCARY! as it is!

 

[kungpaoshizi]

Re: How to validate the condition of the wood inside the transom

Is it really that big of an issue? I mean, I've ridden it pretty hard up until now, the only reason I'm asking these question though is because I'm learning all the details of boats in general...
Even if I get the appropriate bolts in to attach to the CMC?

I've basically restored the motor minus new gaskets in the powerhead.. I was going to just refinish the hull, but then I found the screw, and then found pictures of the similar '83 venture model and questioned the wood in the transom...

Should I just get a higher agreed upon value from the insurance company and call it good? lol
When it dies/sink then I just collect? heh

I'm all for putting the work into restoring the transom and innards of the hull since I like the boat overall..
It just sucks because I would have to put most of the work into it in the winter months, so I'll have extra long cure times

 

[smokeonthewater]

Re: How to validate the condition of the wood inside the transom

the way that motor is on there you COULD find it in your lap at WOT.

There is no way to bolt it together safely as is.... you could add a jackplate and make it work and it would be fine but the better solution is a motor that fits the boat

 

[kungpaoshizi]

Re: How to validate the condition of the wood inside the transom

What about a shaft conversion? I know a few mentioned that...
Here's the side pics..

 

[Watermann]

Re: How to validate the condition of the wood inside the transom

I see your mounting issue, that's a bit frightening but no biggie there to fix. I would just get some 1/2" aluminum that is long enough to bolt on down below in the lower holes on the CMC and extend up to the needed height. You may want to also tie in the 2 pieces at the top with a cross piece to make things a bit more solid.

 

[smokeonthewater]

Re: How to validate the condition of the wood inside the transom

Well in those pics it isn't QUITE as scary but still needs attention... the suggestion above is basically a jack plate..... IE a "plate" to "jack" up the engine.... ALSO your motor looks to possibly be a little low still so raising it COULD gain you a little speed....

http://www.explosivepowersports.com/hi-jacker-fixed-jack-plate-jp-4fa-dp/

 

[Chris1956]

Re: How to validate the condition of the wood inside the transom

Kung, OK you have a longshaft '76-'77 Merc Inline 6 motor, mounted on a bassboat that looks to have a 20" transom. The motor originally mounted with 2 hexhead thumbscrews and two 3/8" thrubolts. If you had the original PTT unit, there would be 4 more 3/8" thrubolts, in the PTT brackets. If the motor is mounted to the CMC unit with the two thumbscrews and two thru bolts, I would think it is fine. If you are just using the thumbscrews, you have a problem. However, I see the PTT brackets are bolted on. Without the PTT pistons, those brackets do not take the intended strain. Can you put a piece of angle iron between the lower shock mounts and the PTT brackets to hold the motor from tilting? That should restore it to as close to OEM as possible.

 

[kungpaoshizi]

Re: How to validate the condition of the wood inside the transom

Gonna do measurements here in a sec, after looking closer I see the top second plate is bolted to the cmc, I guess it's a top adapter plate of some sort