Transom Crack Advice

[mac18]

I have a 1997 Viper Cobra 201D 20 foot bass boat that has a few cracks near the top of the transom as can be seen in the photos. There are a few small cracks in the splash well too. Other than that, there are no other cracks anywhere below the rub rail. I do have cracks in the top cap gel coat but from many other posts in the Cobra Forum it sounds like the rivets in the top may be loosening causing flex issues and is cosmetic. I will pursue this issue too but want to get some advice on the transom first. I am thinking of repowering this boat with a new Mercury 250XS four stroke and am wondering if these cracks indicate there could be issues with transom rot and maybe this boat isn't a good choice for repowering. The cracks have been there for a long time and don't seem to be getting worse. I don't notice any soft spots or weeping or discolored areas. I can stand on the cavitation plate and bounce up and down and the transom seems very solid. Currently I have a two-stroke Mercury 200 EFI on the boat which is about 80lbs lighter than the new four stroke would be. Curios to get some opinions, thanks.

[AndrewM-Fishing]

It's really hard to say but I'd pull one or two of the mounting bolts and investigate. Dry is good, wet is bad.

[rojoguio]

It flexed to crack the gel like that. Movement needs to be investigated. Does your hull have a transverse brace below the splashwell or is the splashwell designed in, to be part of the forward thrust support, for the upper section of your transom?

[mac18]

It's really hard to say but I'd pull one or two of the mounting bolts and investigate. Dry is good, wet is bad.

Sounds like a good idea. Should probably pull the U-bolt the trailer tie down hooks into as well.

[paulrodbender]

I drilled a couple of small holes on the inside of my transom and waited for water to drip out, which it did.

[mac18]

It flexed to crack the gel like that. Movement needs to be investigated. Does your hull have a transverse brace below the splashwell or is the splashwell designed in, to be part of the forward thrust support, for the upper section of your transom?

The splashwell is just molded in and not attached directly to the angled bracing that attaches into the floor of the battery/bilge well and down into the hull. One of the photos shows the bracing with the batteries removed, the bolt in this photo is from the lower starboard part of the jack. plate.splash well.jpgtransom cut out.jpginside transom.jpg

[rojoguio]

Ok, if no brace transversely right below the Splashwell on the inside then the Splashwell is the Brace. Some boats are made like that. This being said the Splashwell is Not shaped for the engine to roll forward (Lower unit contact with a solid object underway) allowing for the flex. Your glass fibers may be fine, they do deflect a bit before cracking. Gelcoat is the waterproofing so if you have a wood transom, no rot, better get the cracks fixed or you will have rot in the future. Champion glassed in a 2x4 on edge across the transom under the splashwell and the knee braces were glassed to that transverse brace as well as the transom tying everything together. You look at my little Blazer project pictures and you will see I added the transverse brace to it while the opportunity presented itself. I smoked a tree with my other Blazer and not only did the gelcoat above the splashwell crack but the splashwell compressed too cracking all the gelcoat inside.

[mac18]

Ok, if no brace transversely right below the Splashwell on the inside then the Splashwell is the Brace. Some boats are made like that. This being said the Splashwell is Not shaped for the engine to roll forward (Lower unit contact with a solid object underway) allowing for the flex. Your glass fibers may be fine, they do deflect a bit before cracking. Gelcoat is the waterproofing so if you have a wood transom, no rot, better get the cracks fixed or you will have rot in the future. Champion glassed in a 2x4 on edge across the transom under the splashwell and the knee braces were glassed to that transverse brace as well as the transom tying everything together. You look at my little Blazer project pictures and you will see I added the transverse brace to it while the opportunity presented itself. I smoked a tree with my other Blazer and not only did the gelcoat above the splashwell crack but the splashwell compressed too cracking all the gelcoat inside.

Ok I just had the privilege of going through your Blazer post. It surly is a lesson in boat construction and helps me think about what is going on with my rig. Now I see what you are talking about with the transverse brace. I appreciate your input, THANKS.

[rojoguio]

Thanks for the comments. Manufacturers Tab in the spashwell to the transom but the tabs seem to do more to stabilize torque to the cap than anything else. You can find posts here where guys are pulling their caps and almost always it's the tabs holding the cap at the transom. Check the transom core integrity first, if it's solid fix the gelcoat, the rest of the boat design you just live with till the cap is off. I've been fishing out of a little Blazer with a rotten stringer system for years now, I just don't push the hull to the point it starts flexing and twisting. Short of a Punch Thru it will be on Ross Barnett for years to come or till my Champion gets finished.......whatever comes first. Lol.

[mac18]

I drilled a couple of small holes on the inside of my transom and waited for water to drip out, which it did.

That sounds like a good idea. In the next week I will pull out all the batteries and subfloor to get at some of the jackplate bolts and will drill a small hole from the inside if none of the pre-existing bolt holes look wet. Thanks for the input.

[mac18]

Thanks for the comments. Manufacturers Tab in the spashwell to the transom but the tabs seem to do more to stabilize torque to the cap than anything else. You can find posts here where guys are pulling their caps and almost always it's the tabs holding the cap at the transom. Check the transom core integrity first, if it's solid fix the gelcoat, the rest of the boat design you just live with till the cap is off. I've been fishing out of a little Blazer with a rotten stringer system for years now, I just don't push the hull to the point it starts flexing and twisting. Short of a Punch Thru it will be on Ross Barnett for years to come or till my Champion gets finished.......whatever comes first. Lol.

I should be able to get a good feel for the transom integrity. Now my only other issue with the hull is the top cap cracks. I will get some photos and make a post soon. Hope you get to put that Blazer in the water soon!