247 Advance transom issue

Primo

New Member
Joined
Aug 7, 2023
Messages
4
Reaction score
0
Points
1
Age
39
Model
Advance
I own a 1999 247 advance. It was purchased used this summer and I would like to repower the boat. The boat currently has a Yamaha 250 ox66. Looking at the transom, there is bulging on either side of the engine. I can see separation between the outer glass and the rest of the transom from the bang cap. My question is, is the transoms completely compromised or can this be clamped back together with a more robust bang cap?
 

Wild blue

Active Member
Joined
Jan 14, 2024
Messages
42
Reaction score
10
Points
8
Age
43
Model
Sailfish
I own a 1999 247 advance. It was purchased used this summer and I would like to repower the boat. The boat currently has a Yamaha 250 ox66. Looking at the transom, there is bulging on either side of the engine. I can see separation between the outer glass and the rest of the transom from the bang cap. My question is, is the transoms completely compromised or can this be clamped back together with a more robust bang cap?
Sounds like you need some repair if nothing else, generally it’s never a good idea to bury rot of any kind, if you caught it early enough a good repair guy can carve out the bad and repair if it’s surface, my experience is it you have to dive into it to really know
 

Primo

New Member
Joined
Aug 7, 2023
Messages
4
Reaction score
0
Points
1
Age
39
Model
Advance
Anyone know if transoms from this year were made of wood or composite? Is there any way to fix the delaminating without replacing the whole transoms? We lifted the motor to check if the transom flexed, it was solid. No flex at all
 

Wild blue

Active Member
Joined
Jan 14, 2024
Messages
42
Reaction score
10
Points
8
Age
43
Model
Sailfish
Anyone know if transoms from this year were made of wood or composite? Is there any way to fix the delaminating without replacing the whole transoms? We lifted the motor to check if the transom flexed, it was solid. No flex at all
I found this on the hull truth site…

“Around 1999-2000 they stared using greenwood XL plywood which is a composite wood material that supposedly doesn't rot and carries lifetime warranty against it. Transom could still get wet though through the aluminum cap or poorly sealed mounting bolts, which could in theory, cause the fiberglass to delaminate over time”
 

Hookup1

GreatGrady Captain
Joined
Oct 16, 2007
Messages
3,035
Reaction score
855
Points
113
Age
70
Location
Cape May, NJ
Model
Islander
Go to GW Factory for answers. Everything else is hearsay.

From your description the transom is wet and swelling. It's not made out of composite materials. They don't fail immediately. Look for cracks along rub rail, back well and vertical cracks on outboard side of transom. Start budgeting for a complete transom rebuild.
 
Last edited:

seasick

Well-Known Member
Joined
Aug 19, 2008
Messages
9,530
Reaction score
1,420
Points
113
Location
NYC
Also note that the 'bang' cap doesn't really hold the transom sandwich together structurally.
It is more of a sealing cap. I suspect that your transom is shot. How far the rot extends is the question bur based on your observations, it seems that the problem may be extensive. In cases where the rot is more localized, some folks have dug out the rot and used a pourable material ti fill the space. I don't think that is a good choice in most situations for a few reasons. The main reasons are that it it very difficult to remove all the rot especially from the inner sides of the fiberglass and it is also difficult to get the pour to fill every void.

What you can do is drill some smallish holes in several areas to see if the coring is rotten. If the extern of the rot is extensive, the transom needs to be rebuilt. You could get a fiberglass specialist to take a look and offer advice.
 

Ekea

Well-Known Member
Joined
Aug 11, 2020
Messages
634
Reaction score
214
Points
43
Age
39
Location
Mid Atlantic
Model
Chase
definitely not composite. by over 10 years.

its very hard for us to give good advice beyond that without seeing the transom or at least pictures of the transom. what you describe does sound like wood that is swollen and holding water. an inspection from a good fiberglass shop should probably be your next move.
 

Bg56126

Well-Known Member
Joined
Jun 17, 2013
Messages
63
Reaction score
20
Points
8
Location
Mystic, CT
Model
Express 330
I had a 99' 272 Sailfish which had a similar problem as you are describing a few years back. I had my dealer fix it. They were able to pull the motors & cap, carve out the rot, fix it (not sure exactly what they did) and reseal everything so it would never be a problem again. They then put a new cap on it. Fortunately, we caught it before it required a whole new transom but you won't know the extent of the work until they get the cap off and can see how much rot is in there.
 
  • Like
Reactions: ErikL

DennisG01

GreatGrady Captain
Joined
Sep 1, 2013
Messages
7,189
Reaction score
1,341
Points
113
Location
Allentown, PA & Friendship, ME
Model
Offshore
My mother's boat had a similar thing going on a few years ago. I removed the engine and verified the wood was still in good shape by drilling multiple holes and inspecting. There was no flex in the transom, either. I contemplated skinning the outside of the transom to rebuild, but decided on a different approach as I was reasonably sure the transom core was fine.

I infused resin into each hole I had drilled to seal it up. I then bought 1/4" SS plates and created multiple "backer plates" for both the inside and outside of the hull to be double sure there would be no issues with structural integrity. I cut two large squares (maybe 10") for the outside and two wide rectangles (from memory, roughly 3"x24" or 30") for the inside. One rectangle was used on the inside of the transom lip where the the motor mounts and the other rectangle was used further down the transom on the inside. Thru bolts were used to shore everything up.

As mentioned, the bang cap has absolutely nothing to do with structural integrity. You would need to fab a bang plate that is U-shaped and thru-bolt it through the transom. But that may not be enough.

Based on the info you have provided, though, it's hard to say what you will need to do to fix it. Best bet, if this is not something you're comfortable with, is to get it checked out by a reputable repair facility.
 

wlewis

Well-Known Member
Joined
Jun 19, 2008
Messages
266
Reaction score
13
Points
18
Location
Savannah, Ga
Greenwood XL plywood started in 97 or 98, I believe. It’s no rot wood, not composite. The wood itself has a lifetime warranty for the wood itself, no labor or other materials, warranted by Greenwood, not Grady.