Outboard mounting bolts over tightened at factory, or soft transom?

[sutor623]

Hey guys just wondering about these stress cracks. There is no transom flex when the motor is fully tilted up and we move it. There are NO stress cracks anywhere else on the boat. Transom feels solid. It seems that these bolts have been overtightened from the factory.

I removed one of the upper bolts with the motor supported, and there is a marine epoxy all around inside the bolt hole so I cant see/feel the wood right around the bolt. I pulled the drain plug fitting and the wood in the transom down there is solid when I hit it with an ice pick. This boat has been stored under cover for most of its life and is a trailer queen. Boat is a '95 Sunbird Neptune. Stringers look good (from what I can see in the fuel hatch), floor is solid. There is no sign of rot in this boat from the areas that are accessible. I have no way to pull the cap off this boat so I am hoping this isnt going to be a transom rebuild. Id like to get 3-5 years out of her.





Back Side: No sign of cracks/stress

 

[Scott Danforth]

The factory would not have epoxied the holes. They would have simply drilled them, bolted the motor on and slapped it on its way. The epoxy was added later. I suggest you drill a few test holes

 

[sutor623]

Where should I drill, and with a hole saw or a drillbit? I have two scuppers maybe i should just remove
Them and check?
I also happen to know the first owner of this boat and he is a good friend. He told me it is the factory motor and had never removed/installed it. Whatever I dug out of the screw holes is a gray putty like substance. Very strange.....

 

[MTboatguy]

Even on a good solid transom, you are going to have movement of that engine when you are trailering and those cracks look like the small amount of flexing that the engine is transmitting to the transom. Those are gel coat cracks and on boats that rock and roll no matter what we do to them, I have see it quite often. I am kind of a rebel, but I probably would not be worrying to much about it, when it comes to gel coat, it does not take much concentrated pressure to crack it.

 

[jbcurt00]

I was thinking no transom saver or a really rough ride to the end of the ramp. I know lots of people who store their boats less then 5min from a ramp. Only break out the saver for the end of season trip home or a longer haul then 5min to the ramp


Gray stuff in the motor mount thru holes, wonder what that is...butyl caulk maybe?

 

[sutor623]

Even on a good solid transom, you are going to have movement of that engine when you are trailering and those cracks look like the small amount of flexing that the engine is transmitting to the transom. Those are gel coat cracks and on boats that rock and roll no matter what we do to them, I have see it quite often. I am kind of a rebel, but I probably would not be worrying to much about it, when it comes to gel coat, it does not take much concentrated pressure to crack it.

Thanks for the reply! I sure hope you're right!! I'll tell us what, I have seen wayyyyyyy worse. When I bought this boat I wasn't really that worried about it cause it really didn't look that bad.

 

[MTboatguy]

I have seen guys rip a transom out and it was very obvious why it happened, I just went out with a friend on Wed in his boat and noticed some cracks very similar to what you had, so we looked it over, bounced the motor, moved things around and deemed it still solid. Gel coat makes a pretty boat, but it has nothing to do with the structure of the boat, so normally I don't worry to much about it, I have seen boats you could sneeze on and crack the gel coat. Like I said, I am a rebel and would not worry about it, if you start getting glass cracks, then I would start investigating a bit deeper to see what is going on.

That said, go have a good time, when the season is over, then take out that fine toothed comb, perhaps drill a few test holes and get deeper into it. We have to face facts, boats go through a hard life of pounding and towing, they are going to develop some cracks along the way, you can't avoid it.

 

[jbcurt00]

Yep ^^^

a hard fast run into rough water would also strain the motor mounts.

 

[sutor623]

I was thinking no transom saver or a really rough ride to the end of the ramp. I know lots of people who store their boats less then 5min from a ramp. Only break out the saver for the end of season trip home or a longer haul then 5min to the ramp


Gray stuff in the motor mount thru holes, wonder what that is...butyl caulk maybe?

JB, actually when I bought the boat it did NOT have a transom saver..... Got one now and yea that's what it looks like butyl caulk. Actually it looks like the same stuff they sealed
The deck to the stringers with.....

 

[jigngrub]

I personally would suspect a soft transom because of the boats age.

Remove those scuppers and have a look, also drill 1/4" dia. inspection holes 1 inch below the engine mounting bolts on the inside of the transom. You know what dark and wet or just wet wood means don't you?

I don't trust the tapping/knocking/beating on the transom for a solid or soft sound, nor do I have faith in the bouncy-bouncy on the motor leg. Looking at drill shavings from strategically placed inspection holes will tell you the truth.

Edit:

By the way, that is a very shoddy installation job on that motor. Washers only don't give the motor and transom the support they need, I see lots of people doing it that way, but they're doing it wrong.

These are OEM on just about all new outboard motor boats, and there's a good reason for that:
http://www.iboats.com/Transom-Suppor...iew_id.1185373

They come in 2 sizes, one for the top set of holes and the other for the bottom set of holes.

 

[Woodonglass]

Since you did the "Raised Motor Bounce Test" AND the "Remove Mount Bolt" test and both were negativ appears to be typical gel coat stress cracking due to improper bracing during transport or from torquing or hitting submerged things during boating. The large washer is TYPICAL and PROPER installation methods for the era of your boat. I suspect 95%+ of all boats of that vintage were done that way. Nothing Shoddy about it. Just the way it was done back then. The mfg's have since learned there are better methods and have updated them. You could repair the stress cracks but no guarantees they won't reappear. If you use a Transom Saver for transport from now on and don't hit any submerged objects They prolly won't get any worse. Keep an eye on em and keep enjoying your boat. That's my opinion and it's worth every penney you paid for it!!!!

 

[MTboatguy]

That's my opinion and it's worth every penney you paid for it!!!!

And to say, That is a priceless opinion in my book! You can't pay enough for information this good!

 

[sutor623]

Thanks guys, y'all are awesome!!!

 

[jigngrub]

Thanks guys, y'all are awesome!!!

You're quite welcome Pete!

How's my brown dog doing?

 

[sutor623]

You're quite welcome Pete!

How's my brown dog doing?

She's doing great! Still loving boating. She likes
This new one better. Sold the Starcraft cause I wanted something bigger. Guy got lucky!!! That floor
And transom will last another 10 years of he takes care of it thanks to your advice. Spar urethane really did the trick.

 

[sutor623]

By the way I'm going to retrofit those t and h mounts on top and bottom bolts and see how she does this year. If I get more stress cracks ill plan on a new transom, but if it holds up, I'll let her fly!!!

 

[sutor623]

So fellas, I installed the T and H mounts on the top bolts, and noticed that the transom had a little bit of a curve in it from one bolt to the next. I decided to pull the scuppers, and sure enough the wood was wet in there. I dug at it with a screwdriver and it really didnt seem soft. It was a little soft in the very center where the two pieces of wood meet. I let it dry out all day today and the wood feels dry and solid. Tapping around the transom the only spot that sonds iffy is right below where the motor mounts. Oh and by the way, the wood in this transom is 2.5" thick!!!

Kind of a poor design back here because whatever water doesnt drain out of the scuppers sits up around the bottom two motor mount bolts and the seal of the scuppers.

Here are some pics:

See that little ledge where water can collect? Also note the T and H bar







So what do you guys think? Doesn't seem like rot has really set in, although it is definitely a ticking time bomb. I am a little leary of taking a core sample out but am not totally against it. If I took one it would be out from just under the motor bracket. When I drilled out the places to mount the trim tabs the wood that came out was not rotten. It was a light color and seemed to be dry. Not saying much, but just another piece of info.

 

[sutor623]

I have been digesting the possibility of redoing this transom. The stringers and floor on this boat are solid. I am invested in it and it will be a fine fishing vessel!!

1.) I do not have the means to pull the top cap. Also, the way the hatches are back there it would be less than ideal to cut the top cap. I tend to overdo things but cant really afford to do this time-wise because I have a 10 month old little girl.

2.) I dislike and am not very good at doing much fiberglass work. I would like to avoid cutting the rear skin off the boat to replace the transom with glassed wood.

3.) I have looked into Seacast and NidaCore and they are very expensive. With my 2.5" thick XL transom I am looking at 25 gallons and Seacast quoted me $1200 shipped (just over $200 per 5 gallons). I have run out of most of my funds for this boat and just cannot pull the trigger for $1200 smackers. It does seem, however, that doing a poured composite transom will prevent future rot as well as eliminate any serious glass work.

Is there any way to get ahold of or make a cheaper pour in type transom?



Here is what it looks like in the compartments. You can see how it would be hard to get to the transom, but it would be possible to pour into here. This is port side as you can see the lip of the transom swings up and around.

 

[jigngrub]

Reality check, your boat is 20 yrs. old. Over the next 5 yrs. you'll see more and more degradation.

I suspect your boat has more water intrusion problems that you know or care to admit (denial). If you'll look back at the pics you took when you first got your boat you'll see quite a bit of black mildew in it, that's not a good sign.

You can't truthfully say that your deck and stringers are solid and your foam is dry until you lift the decking and check everything out. There may not be much rot in there right now, but I'd be money there is plenty of wet stuff under your deck that is the same ticking time bomb that you have on your transom. All of this stuff is typical for a 20 yr. old fiberglass boat that hasn't been kept garaged or covered when not in use.

IMO, Seacast isn't worth the money unless you plan to keep the boat for a very long time.

If you don't like doing fiberglass work, you should own a brand new fiberglass boat or an aluminum boat. Older fiberglass boats are nothing but a bunch of work and money until you tear them apart and put them back together with new and dry material.

 

[Yacht Dr.]

Meh..If it were mine..Id run it for the season. After that I would take the motor off and grind where them bolts are to inspect whats going on. Go from there type thing.

Happy boating