18 ft kaboat/10 hp copperhead

mainer_in_ak

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With the 18 ft model and three men, the rig pushed a top speed of 13 mph. The 18 ft model ran best with about 9 psi in the floor, and 4 psi in the tubes. anything lower in psi, it decreased top speed. I measured the boat to be 53 inches in width. Stand-up paddling pushed it around at good pace. The prop clears the tubes by about 4 inches. One thing that I'm going to do though, is adjust the spherical ball joints on the motors, to get the prop to ride about 1-2" deeper in the water. Most small boats have a 13 degree transom (or somewhere close). The kaboat has a straight transom, so I couldn't get the prop as deep in the water as I would like. That's one of the good thing (of many) about the copperhead design, is that you can adjust them.
 

mainer_in_ak

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I'm beginning to loose track of how many different square stern and freighter canoes I've run in. And now, floaty toys. I would take one of these with a surface drive, any day of the week over a "jet ranger". When it's all said n done, you can consider this the jet ranger killer. New technology, better on fuel, more load carrying capacity. would be a skookum rig for guys that want to hunt PWS creeks n rivers from a big boat, OR guys hunting from big jet boats, that want to take their pursuit up shallow creeks.

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Troy Sharp

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How do they do with skinny swift water. 4-8 inches rock and say bottoms?
 

Sid

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Looks good on the water, was that last Fall ? it is not this year ? SID :proud:
 

mainer_in_ak

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How do they do with skinny swift water. 4-8 inches rock and say bottoms?

I got a pm from a couple guys regarding this set up. Anyhow, I did run a 23 hp copperhead on the 18 ft kaboat. We went so far up the 20 mile river, that the braids were too skinny for the 53" wide boat. We passed all sorts of jet boats that were grounded out. The tubes limit the amount of steering you have, so you have to really be on your game. We couldn't' use the motor much past half throttle, or it would slinky/destort the floor and burp water. I'd like to get another one someday, and have a custom frame built for it. Due to the straight transom, I ended up canting the motor with a special spacer, as the motors are designed for a 13 degree transom angle, and the prop doesn't bit deeply enough when the boat planes.

going with a tiny jet pump is a no-go in my opinion, you've no load carrying torque. Surface drive works better, and you don't have to do all these altercations/modifications that void the warranty.
 

Yukon Cornelius

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I got a pm from a couple guys regarding this set up. Anyhow, I did run a 23 hp copperhead on the 18 ft kaboat. We went so far up the 20 mile river, that the braids were too skinny for the 53" wide boat. We passed all sorts of jet boats that were grounded out. The tubes limit the amount of steering you have, so you have to really be on your game. We couldn't' use the motor much past half throttle, or it would slinky/destort the floor and burp water. I'd like to get another one someday, and have a custom frame built for it. Due to the straight transom, I ended up canting the motor with a special spacer, as the motors are designed for a 13 degree transom angle, and the prop doesn't bit deeply enough when the boat planes.

going with a tiny jet pump is a no-go in my opinion, you've no load carrying torque. Surface drive works better, and you don't have to do all these altercations/modifications that void the warranty.
Mainer I've been wanting to contact you about some of these smaller surface drives for my 15' kaboat. Are the transoms able to handle the weight?
 

mainer_in_ak

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The single cylinder 10 hp is the minimum I would recommend. You don't want to over-work the little 6.5 or 7hp engines. Better yet, would be the 12-14 hp engines.
 

North61

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The single cylinder 10 hp is the minimum I would recommend. You don't want to over-work the little 6.5 or 7hp engines. Better yet, would be the 12-14 hp engines.

Well I happen to have a 14 HP hanging around here somewhere! Does the 18 ft Kaboat have a reinforced bottom?
 

kk alaska

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I would try it on the Saturn Kaboat 15 ft Alaskan model I had the first 16 ft Saturn Kaboat in AK and the 15 ft flexes less. I have a frame on my 15 ft model. And it is less sensitive to air pressure and less cavitation with an outboard. The 15 ft has xtra material on the bottom of tubes. Not sure on the 18 ft model.
 

AK DUCKMAN

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I'm thinking about getting one of these. Anywhere a guy can go look at one. Wanting 18 foot and running a 15, 2 stroke Johnson.
 

kk alaska

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Call Brian Richardson at AK Raft Connection 907-250-2271

Would still recommend the 15 ft AK model over the 18 ft. shorter, stiffer less cavitation issues.
 

Yukon Cornelius

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Call Brian Richardson at AK Raft Connection 907-250-2271

Would still recommend the 15 ft AK model over the 18 ft. shorter, stiffer less cavitation issues.
With quite a few upgrades over the 18' as well.
When i contacted him about getting an 18' he strongly suggested the 15' Alaskan model. I'm happy. Very happy. It does have it's limits, since it isn't that wide, but man is that thing stable, and gas efficient.
 

yukon254

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Nice looking rig Mainer...Im in the market for something like that, my only question is how does it perform in rocky creeks rivers? Can you go as shallow as an outboard jet drive?
 

Yukon Cornelius

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Nice looking rig Mainer...Im in the market for something like that, my only question is how does it perform in rocky creeks rivers? Can you go as shallow as an outboard jet drive?
In in rocky rivers area now and I run a 7.5 prop on mine. I was amazed at how shallow I could go. Jet shallow? Not sure but the boat itself barely breaks the subsurface. And I was able to drag it through 6" of water without dragging bottom.
 

yukon254

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In in rocky rivers area now and I run a 7.5 prop on mine. I was amazed at how shallow I could go. Jet shallow? Not sure but the boat itself barely breaks the subsurface. And I was able to drag it through 6" of water without dragging bottom.

Ok thanks. Jet shallow to me is 4 inches or less. Im running a 16ft Lowe with 30-HP ( at the pump) outboard jet. I can easily run in 4-inches of water loaded. Ive been running outboard jets since they were available, both 2 and 4 strokes,and once set up properly they perform very well, but are getting quite expensive so am looking at alternatives. That said I wouldn't be interested if I had to drag it through 6 inches of water.
 

Yukon Cornelius

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Ok thanks. Jet shallow to me is 4 inches or less. Im running a 16ft Lowe with 30-HP ( at the pump) outboard jet. I can easily run in 4-inches of water loaded. Ive been running outboard jets since they were available, both 2 and 4 strokes,and once set up properly they perform very well, but are getting quite expensive so am looking at alternatives. That said I wouldn't be interested if I had to drag it through 6 inches of water.
You could paddle it. Or go with these surface drive. I ended up doing 60miles one weekend. Burned 4 gallons of gas. I simply dragged because I didn't want to risk busting my prop.
Theres a thread on these Kaboats with a jet as well.
But they do have limits. I can load mine up in a beaver and go anywhere. I can take 6 gallons of gas and hunt all weekend. Notwide but super stable.

i should also mention I got across gravel bars that jet boats weren't getting across according to some.
 

Alaskacanoe

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3 years ago my friend drew out on a cow tag up 20 mile. He tried to get up it in a 16 ft aluminum w/ outboard jet, but was turned back by the rapids.
He asked me if I could get him in further as he wanted to get back into areas that had no hunting pressure.
20 mile river can be a tough one for any boat, I have had my Jet ranger up to and touching the actual glacier, and that is as far as a boat can go,
and yes we got a moose and brought it out in one trip.
I have a Kaboat in my rental fleet here on the kenai, and it is not the same type of boat as the Jet Ranger. It is much lighter duty material and I have had to patch it more than a few times as it does not have enough protective layers on the impact zones., ( I blow over Beaver dams in the jet ranger, but would be pretty much a no go in the Kaboat..)
and the floor design is much different, along with the transom design.
I was going to use the Kaboat on my moose hunt on the yukon last year, but decided against it and took the Jet ranger because its just that much tougher and I would rather have a boat designed for a jet than to mess around trying to make the kaboat work with a jet, as it does not have the right transom angle.
both boats will work well , but they are not in the same league as far as my tests have shown.
 
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With the 18 ft model and three men, the rig pushed a top speed of 13 mph. The 18 ft model ran best with about 9 psi in the floor, and 4 psi in the tubes. anything lower in psi, it decreased top speed. I measured the boat to be 53 inches in width. Stand-up paddling pushed it around at good pace. The prop clears the tubes by about 4 inches. One thing that I'm going to do though, is adjust the spherical ball joints on the motors, to get the prop to ride about 1-2" deeper in the water. Most small boats have a 13 degree transom (or somewhere close). The kaboat has a straight transom, so I couldn't get the prop as deep in the water as I would like. That's one of the good thing (of many) about the copperhead design, is that you can adjust them.

I find it interesting how Mainer attempted to compare the performance he is getting from his Kaboat with a surface drive to the 430AJR Alaskan Jet Ranger running a 30/20 outboard jet. When his states his boat runs 13 mph with 3 adults and I've clocked my 430AJR with my GPS at 20 MPH with 4 adults. He also states he needs to drop his prop 2 more inches so it gets a better bite in the water and the 430AJR zips across 2 inches of water and rocky bottoms without a problem. I think the best part of his report was how his trip up 20 mile river came to an end in the braids where he ran out of water, Where I and many of 430AJR owners are driving the Alaska Series 430AJR all the way up to 20 mile Glacier. In addition there is a huge durability factor between the 430AJR and Kaboat. When you're out in the middle of no-where, you can rely on the Alaska Series boat to take a punishment and still get you home.


Jim King
Alaska Series Inflatable Boats,
The Toughest Bottoms in the Business,
River Rafts, Catarafts, Inflatable Kayaks,
Inflatable Canoes, Inflatable Sport Boats,
Inflatable Jet Boats, Tenders and Dinghies.

WWW.alaskaseries.com (907) 248-2900
 

Alaska_Lanche

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You are correct. These boats do not compare. You could buy 6 15' Alaskan Kaboats for the price of one jet ranger ($1100 vs $6900). They are different crafts no doubt. You aren't going to go the places in weedy lakes and slow moving streams in a jet ranger with a outboard jet on it that you are with a Kaboat with a surface drive either.

Both are niche boats and it really comes down to what your niche is.
 
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