A few questions about my Intex Mariner 400 boat

[jwardmagic]

I recently bought an Intex Mariner 400 boat and used it with my 2hp mariner outboard. I noticed a few things. The keel didnt seem to inflate very hard. It wouldnt really hold the boat in shape well when I was sitting at the back with the engine and someone else in the front, the boat would bend in the middle slightly, and secondly, when on full throttle, the motor mount would push into the stern (where the rock guard is) of the boat by a few inches, pulling the engine slightly into the water.
Am I doing something wrong?

 

[Drowned Rat]

Re: A few questions about my Intex Mariner 400 boat

Hi there,

You have just discovered the "Hull speed" of the Mariner 400. There is nothing wrong with your boat, that is just its limitation. The inflatable floor on that boat is not designed to provide a hard planing surface, but rather a more solid walking surface. The top speed of that boat, and ones like it, is about 5 to 8 mph regardless of how much power you put behind it.

 

[jwardmagic]

Re: A few questions about my Intex Mariner 400 boat

Hi there,

You have just discovered the "Hull speed" of the Mariner 400. There is nothing wrong with your boat, that is just its limitation. The inflatable floor on that boat is not designed to provide a hard planing surface, but rather a more solid walking surface. The top speed of that boat, and ones like it, is about 5 to 8 mph regardless of how much power you put behind it.

I understand. So it is normal for it to bend in the middle? Even with two adults and a 2hp engine?

Also, what about the engine pushing into the stern of the boat? Did I not pump it up enough?

 

[Sea Rider]

Re: A few questions about my Intex Mariner 400 boat

If there is a small wooden/metal transom supported by means of brackets on to rear of sib, no matter how well you inflate that 0.5 mm shower curtain fabric water toy, engine will bend against stern, even 0.9 mm boats correctly inflated with same engine supports tends to bend a bit less, but bends nevertheless. Thsi is the issue of not counting with stern traditional long wooden transom secured to tubes as in sibs.

Happy Boating

 

[jwardmagic]

Re: A few questions about my Intex Mariner 400 boat

If there is a small wooden/metal transom supported by means of brackets on to rear of sib, no matter how well you inflate that 0.5 mm shower curtain fabric water toy, engine will bend against stern, even 0.9 mm boats correctly inflated with same engine supports tends to bend a bit less, but bends nevertheless. Thsi is the issue of not counting with stern traditional long wooden transom secured to tubes as in sibs.

Happy Boating

I found this video on youtube of someone with a 5hp engine on their mariner 400cruising along much faster than I did with my 2hp on my mariner 400 and it doesn't seem their engine is tugging much at all on their motor mount brackets and seems perfectly level? http://www.youtube.com/watch?v=kn9fOkv9D7M and also this video http://www.youtube.com/watch?v=N9LH9BarerY&feature=related . Upon searching I found more, and videos of people using 2hp engines on the seahawk II, on what seems like full throttle, with very little problems. http://www.youtube.com/watch?v=EAsrKiO1nP0&feature=related and http://www.youtube.com/watch?v=yCSsiRXi37k Any help?

 

[Drowned Rat]

Re: A few questions about my Intex Mariner 400 boat

The only explanation is that your boat is underinflated.

 

[Sea Rider]

Re: A few questions about my Intex Mariner 400 boat

The sib with Mariner 5 HP tested more than 2 years ago had a much different transom mount, all 4 rubber supports were placed at back of stern. New Intex supports are far better using back stern & tubes for more engine/transom rigidity compared to. Glad to see that this is not an issue any more.

Happy Boating

 

[jwardmagic]

Re: A few questions about my Intex Mariner 400 boat

The sib with Mariner 5 HP tested more than 2 years ago had a much different transom mount, all 4 rubber supports were placed at back of stern. New Intex supports are far better using back stern & tubes for more engine/transom rigidity compared to. Glad to see that this is not an issue any more.

Happy Boating

But in the 5hp mariner 400 video http://www.youtube.com/watch?v=kn9fOkv9D7M the transom mount is exactly the same as mine, and the intex supports and tubes are in the same place as in my boat. The only difference seems to be that they have modified their motor mount with straps, probably to hold the mount and stop it sinking. Maybe I should try this? I have no idea where or what I'd connect the straps too though. Also, maybe adding a foot more of marine ply, to raise the height of the engine? Would that help?