Intex Mariner 4 modifications and Tips

MarvinW

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Joined
Jul 13, 2022
Messages
6
Ahh I get it now, wanted to add something above but it informs me there is a 60m time limit to edit posts... guess I should f5 more often I reckon I wouldn't have seen the edit button anymore ;)

Anyway, different idea.


IMG_20220720_214739_325.jpg

Mount a sheet on the bottom of a 2x4, I'll most likely epoxy them together. Drill 3 holes, one center two on the sides next to the mounting brackets. The hole in the middle, insert a rope tied in an eight so it can't get pulled through. This will be tied to the carrying handle. The two holes on the side will have the rope enter upwards with the knot below, so they can be tied to the mount. I think this will be secure enough.

IMG_20220720_214752_429.jpg

This way the transom won't drag in open water pulling itself down even if the boat is imbalanced. Or, so I'll hope. The only difference between this way and my previous plan is that there is no side wall. I guess if I had a press I could bend a shape which would fit but by hand I am not even going to try.

IMG_20220720_214805_538.jpg

That bottom u piece is just slid on atm, I need to epoxy it and drill two holes through it and the transom so I can mount the sheet. I'll try to fold the sheet over once so there is no sharp edge possible and I have some more material there and drill two holes to match the transom holes so I can bolt them together with some wingnuts.

Also should really consider setup time, it's going up a lot already. Portability is nice but not if people have to wait an hour at the water side ( exaggeration and also, I'm sure I'll get better at it ;) ).

What do you guys think, is this a better idea? Do I even need to bother with the metal? I mean, that transom is acting both like a floating anchor if it hits the water, as well due to the angle it will pull itself under lifting the nose of the boat, so I *think* diverting the water around it would sure lower that drag..?


Will this all eventually come together and make my Mariner 4 'exciting' ( ed: go vroom ) for a 15y old autistic kid who understands I live on the fifth floor of an apartment building and have limited transport capability? That being said, I *have* to not be able to exceed 20km/h or I might get busted since you need a license for anything capable of doing that... but which water officer would assume a Mariner 4 would do that anyway?

Heck I'm not even sure I can't be fined for exceeding safety limits on the engine size...

I'll be happy if I get 15km/h top, it's not like we don't have a 6km speed limit on most waterways anyway.

*edit: just had a scary thought, if I ever have a structural failure of the transom ( or a boat runs into it... ) the sheet metal is a likely danger no matter what I do to connect it. The sturdier I make it, the stronger the force which will be exerted if it fails.

Maybe I shouldn't use metal but fabric. I could even cut up that really cheap inflatable I have in my closet where I lost a valve from and which is actually therefore useless, and use that. It's allot easier to attach and manipulate.

I think that's the way forward.

Also, I'm thinking I don't know exactly which prop is on it but the previous owner did say it was a lot heavier as my inflatable. Will I gain from making sure I'm running the highest pitch prop ( aka the one for the lightest load )? I know high pitch increases top speed at the cost of 'whole shot' ( yes, I have read some things on the internet... that's it though ). How does that translate to the Mariner 4? I mean, I don't think you can plane without a wood floor since it will bend to much with the slat floor? Ofc the steel pipes extending to the oar locks do help but that's only the back of the boat.


That's the 9 pitch prop, according to the manual it fits light loads. At max, with the boat itself and the mods, two kids say 100kg together and me 62kg, 20kg motor + 2.5kg gas ( internal ) + 5kg/10kg Jerrycan with gas and some extra's like inflatable sup boards and lunch/drinks/'toys' say 50kg miscellaneous, that's <~ 300kg.


That would still fall under a light load I think for the engine, but I can't find any explanation or charts what they deem as light/medium/heavy loads. I guess because hull shape has a lot of influence, the Mariner 4 when I row it actually is pretty nimble unlike the Excursion 4 which is just a turd even with a wood floor it handles like crap due to not having a keel.



 
Last edited:

Andy_Capp

Recruit
Joined
Jul 17, 2022
Messages
2
Ahh I get it now, wanted to add something above but it informs me there is a 60m time limit to edit posts... guess I should f5 more often I reckon I wouldn't have seen the edit button anymore ;)

Anyway, different idea.


View attachment 366087

Mount a sheet on the bottom of a 2x4, I'll most likely epoxy them together. Drill 3 holes, one center two on the sides next to the mounting brackets. The hole in the middle, insert a rope tied in an eight so it can't get pulled through. This will be tied to the carrying handle. The two holes on the side will have the rope enter upwards with the knot below, so they can be tied to the mount. I think this will be secure enough.

View attachment 366088

This way the transom won't drag in open water pulling itself down even if the boat is imbalanced. Or, so I'll hope. The only difference between this way and my previous plan is that there is no side wall. I guess if I had a press I could bend a shape which would fit but by hand I am not even going to try.

View attachment 366089

That bottom u piece is just slid on atm, I need to epoxy it and drill two holes through it and the transom so I can mount the sheet. I'll try to fold the sheet over once so there is no sharp edge possible and I have some more material there and drill two holes to match the transom holes so I can bolt them together with some wingnuts.

Also should really consider setup time, it's going up a lot already. Portability is nice but not if people have to wait an hour at the water side ( exaggeration and also, I'm sure I'll get better at it ;) ).

What do you guys think, is this a better idea? Do I even need to bother with the metal? I mean, that transom is acting both like a floating anchor if it hits the water, as well due to the angle it will pull itself under lifting the nose of the boat, so I *think* diverting the water around it would sure lower that drag..?


Will this all eventually come together and make my Mariner 4 'exciting' ( ed: go vroom ) for a 15y old autistic kid who understands I live on the fifth floor of an apartment building and have limited transport capability? That being said, I *have* to not be able to exceed 20km/h or I might get busted since you need a license for anything capable of doing that... but which water officer would assume a Mariner 4 would do that anyway?

Heck I'm not even sure I can't be fined for exceeding safety limits on the engine size...

I'll be happy if I get 15km/h top, it's not like we don't have a 6km speed limit on most waterways anyway.

*edit: just had a scary thought, if I ever have a structural failure of the transom ( or a boat runs into it... ) the sheet metal is a likely danger no matter what I do to connect it. The sturdier I make it, the stronger the force which will be exerted if it fails.

Maybe I shouldn't use metal but fabric. I could even cut up that really cheap inflatable I have in my closet where I lost a valve from and which is actually therefore useless, and use that. It's allot easier to attach and manipulate.

I think that's the way forward.

Also, I'm thinking I don't know exactly which prop is on it but the previous owner did say it was a lot heavier as my inflatable. Will I gain from making sure I'm running the highest pitch prop ( aka the one for the lightest load )? I know high pitch increases top speed at the cost of 'whole shot' ( yes, I have read some things on the internet... that's it though ). How does that translate to the Mariner 4? I mean, I don't think you can plane without a wood floor since it will bend to much with the slat floor? Ofc the steel pipes extending to the oar locks do help but that's only the back of the boat.


That's the 9 pitch prop, according to the manual it fits light loads. At max, with the boat itself and the mods, two kids say 100kg together and me 62kg, 20kg motor + 2.5kg gas ( internal ) + 5kg/10kg Jerrycan with gas and some extra's like inflatable sup boards and lunch/drinks/'toys' say 50kg miscellaneous, that's <~ 300kg.


That would still fall under a light load I think for the engine, but I can't find any explanation or charts what they deem as light/medium/heavy loads. I guess because hull shape has a lot of influence, the Mariner 4 when I row it actually is pretty nimble unlike the Excursion 4 which is just a turd even with a wood floor it handles like crap due to not having a keel.
Enjoying your posts as you figure out how to add structural integrity to the transom to accommodate your heavier motor. Keep up the good work and let us know how your mods are going.
 

MarvinW

Cadet
Joined
Jul 13, 2022
Messages
6
Took her out today, had a blast!

Cruising at 8-10 km/h at very low rev's is quite relaxing. Hull stays nice and level. If I push past that, the bow comes up and the whole boat starts to bend and weave. It would behave so much better with a solid floor but that's just not portable enough.

When I hit 14km/h sometimes the boat just is so wavy that my prop suddenly pulls in air and I over rev like crazy.

If I position my body weight a bit towards the piece of the boot acting the most like a banana.. it actually get's on plane. I'have multiple runs reaching 18km/h steady, and out of recording I've hit 19.2km/h for a split moment.

I think it might have to do with there being a wake at the end of the boat itself. BEFORE the engine, this and the bendy nature create a large wake which pulls water away from the prop. It sits at a perfect level for going 0-10km/h, but I think it would run a lot better if I lower the transom a couple of cm when I want to go fast.

The rods held up ok. Not great, there is a slight weave in them to so I guess 16mm diameter 3mm thick steel rods aren't enough. Perhaps I will get another length of pipe with an inner diameter of 16mm so I can just slide them over the existing one's after the stop blocks on the back tube all the way to the oarlocks. The first part is the steel and the alu rods which come stock, those are perfectly straight so I don't need to add a lot of strength to the other section either.

I'm a bit worried about my 'partial floor' it's putting quite some strain on the tubes at the back and I'm noticing it's pushing the floor back a bit. Which is, weird enough... exactly the point where the boat settled at top speed. Only the back piece of my floor was in contact with the water. Which just enforces my thoughts that if I had a solid floor the boat would behave a> better b> predictable when getting close to plane. As many no doubt have found out before me, this boat's limits are it's lack of rigidity.

It can be fixed, just make a solid floor. But for me that's not possible I can't transport wider pieces as shown already.

Optionally though, I could get my 3piece hinged floor for my Excursion 4 and cut that up so I have 3x40cm wide section on hinges, cut to the shape of the back of the bout and providing a better surface for the boat to plane on as well as fitting on my bike trailer ( btw, got some comments today about the setup, friendly but they did question my sanity and asked how fast I can pedal it over a bridge.. I said I tend to avoid those :D ).

I'm uploading some video's to my yt channel, two shorts and one couple of minutes one where you can also hear the issue about the prop sucking in air if the boat 'weaves / bends wrong '. That is really scary, I was afraid I'd kill the engine doing that often.

I noticed I had some setting wrong and my content was meant 'for kids' so comments are disabled on the video's.


-> long video. The thumbnail is what I ended up using for bottom transom support, worked fine.


 

MarvinW

Cadet
Joined
Jul 13, 2022
Messages
6
Enjoying your posts as you figure out how to add structural integrity to the transom to accommodate your heavier motor. Keep up the good work and let us know how your mods are going.

Thing is, it's rather 'easy' if you're going to put the boat on a trailer. A sufficiently thick wood floor both increases handling by tons and tons, as well of offering a way to not tax the tubes themselves with the motor torque by connecting straight to the floor.

But that isn't transportable unless you have a trailer, a big van or a big car ( and then you probably put hinges on it so it folds ).

Thing is, what do you want to do with it? If you plan on cruising 14km/h+ ( which seems to be the point the boat starts to plane ) I think a solid floor is a must . If you're content with 12km/h or less you don't need to. But if you want to go exactly 12km/h, I think because of the resistance at that speed you're burning way more fuel as when pushing past that and going the extra speed.

Then again.. speed limit is 6km/h almost everywhere anyway.
 

MarvinW

Cadet
Joined
Jul 13, 2022
Messages
6
Thank you, if it's meant for me lol.

Don't take anything as say as being 100% right, my experience is extremely limited. I am actually counting on more knowledgeable people to come in and correct or supplement me.

I've found video's with Mariner 4's going way faster, all with wooden frames and for instance one with a 25hp motor going 20mph+. As long as you stiffen up the boat and have a mount which doesn't just hang off the back it seems you can do crazy stuff.

Not sure how long those will last, as the load on the tubes isn't what the factory has rated them for. Wouldn't want to burst a seem at those speeds.
 
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