Transom Leak & Aftermarket Power Trim

bloyet03

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Joined
Feb 25, 2014
Messages
26
I have a 1989 TX17pro with a 40HP Johnson on it. I have noticed it takes on a bit of water everytime I have it in the water. I think I have it narrowed down to the transom and more specifically the bolts going through the transom to mount the outboard on the boat. I want to reseal these just to find out for sure but I'm getting mixed information on the internet as to what to use to seal it up. Sounds like 3M 4200 is what I want. What does the forum recommend?

Also, I have been looking at aftermarket trim/tilt for the boat. I'm not 100% comfortable with the CMC style as this looks to put added stress on the transom due to the outboard being further back. However, i know my boat is rated for a larger outboard so, the stress is probably still in spec. Has anyone had any experience with these? Any other suggestions as to what to look at? I'd like to have power trim but don't want to pay $1400 I was quoted for factory.
 

greenbush future

Lieutenant Commander
Joined
Aug 28, 2009
Messages
1,814
4200 should seal it well, and also allow you to remove the bolts in the future too. Most outboard bolt patterns are higher up on the transom and "usually" don't contribute to water entering. It depends how low the transom sits in the water to really tell. Pictures are worth a ton when seeking help here.
 

Woodonglass

Supreme Mariner
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Dec 29, 2009
Messages
25,924
I'd recommend "Core Sampling" your transom first. You do this by drilling 1/4" holes into the transom "On the inside" about 1" deep , down low at various locations and check the drill shavings. If they come out dark and wet then those motor mount holes have been leaking for quite some time and your transom is wet and will eventually rot. It needs to be replaced and your assessment about the extra stress could be correct. With a good Solid Transom the CMC T&T units are excellent units and work really well. You might check Ebay for used units as well. But again, I'd core sample the transom. If it turns out the shavings are dry then fill the holes with 3M 5200 which is a Permanent sealer. The 3M 4200 is a Non Permanent sealer which is perfect for sealing the motor mount bolts.
 

bloyet03

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Joined
Feb 25, 2014
Messages
26
4200 should seal it well, and also allow you to remove the bolts in the future too. Most outboard bolt patterns are higher up on the transom and "usually" don't contribute to water entering. It depends how low the transom sits in the water to really tell. Pictures are worth a ton when seeking help here.

Double Post
 
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bloyet03

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Joined
Feb 25, 2014
Messages
26
4200 should seal it well, and also allow you to remove the bolts in the future too. Most outboard bolt patterns are higher up on the transom and "usually" don't contribute to water entering. It depends how low the transom sits in the water to really tell. Pictures are worth a ton when seeking help here.

I'll try to catch some pictures next time i have it in the water. Its the only place i can see that would be allowing a leak as high as i was seeing it come in. also the sealant that is there looks pretty deteriorated.
 

bloyet03

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Joined
Feb 25, 2014
Messages
26
Well, I pulled the outboard off and resealed the bolts. This helped with some of the water I saw coming down the transom on the inside which i figured it would once I realized the bottom bolts were loose. I found out when the outboard was rebuilt by the previous owner. The mechanic that did the work mounted it with regular silicone. It was no longer sealing the holes, the silicone just fell out. I did find some bad news. The transom is rotten so i guess that's added to list for the winter rebuild project. :frusty: I think I did figure out where most of the water is coming in. I'm going to try and confirm it this weekend. I filled the live well and just for giggles I installed a plug on the outside of the boat after I pulled it out. Water was still slowly flowing into the drain. I'm going to plug it on the outside this weekend and run it like that to see what happens.
 

Watermann

Starmada Splash of the Year 2014
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Jan 12, 2013
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13,747
Yeah be careful running with a compromised transom, the boat isn't seaworthy like that. I'm sure you've seen some of the pics floating around here of people with sunken boats and motors dragging in the dirt behind the trailer with a chunk of transom skin still hanging on.

Also on the 4200 vs 5200 debate. 5200 is not permanent when it comes to a bolt, they turn right out of it. I've used up 3 construction tubes of it on boats and had to take stuff back off later without an issue of it being 'permanent'. Everything on the transom should be set with 5200 not the twice the price 4200.

Oh yeah I have a CMC unit and have nothing but good things to say about how well they operate and I would recommend one to anybody with a smaller HP motor looking for an aftermarket TnT :thumb:
 
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bloyet03

Cadet
Joined
Feb 25, 2014
Messages
26
Yeah be careful running with a compromised transom, the boat isn't seaworthy like that. I'm sure you've seen some of the pics floating around here of people with sunken boats and motors dragging in the dirt behind the trailer with a chunk of transom skin still hanging on.

Also on the 4200 vs 5200 debate. 5200 is not permanent when it comes to a bolt, they turn right out of it. I've used up 3 construction tubes of it on boats and had to take stuff back off later without an issue of it being 'permanent'. Everything on the transom should be set with 5200 not the twice the price 4200.

Oh yeah I have a CMC unit and have nothing but good things to say about how well they operate and I would recommend one to anybody with a smaller HP motor looking for an aftermarket TnT :thumb:

Yeah, it makes me uneasy however, I did play around with it this weekend, it appears for right now its ok. I watched the transom close for ANY movement when I hit it full throttle out of the hole, no movement. I push and pull on it and can't get any flex right now. It will be getting replace this fall/winter when I don't feel like hitting the water due to being cold. For now, its going to be ease into it and baby it.

Actually the 4200 was cheaper. When I redo everything it will be 5200. I might also put a CMC TnT on the boat when I rebuild, depends on the budget. Might be further down the road to. Just bought a house so pretty much BROKE.
 
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