Newbie inboard jet question

Discussion in 'Jet Drives' started by yungcow, Sep 2, 2008.

  1. yungcow
    Joined: Sep 2008
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    Location: Canada

    yungcow New Member

    I'm sure this question must have made the rounds before but please point me in the right direction. What inboard jet packages are available between 75 and 250 HP? This will be installed in a 16 foot aluminum jon modified flat bottom weighing about 900 lbs. It will never have more than 3 people aboard and the most river current it encounters would be a 8-10 knot rapid for 100-200 feet and otherwise a steady 3-4 knot current. I don't want to pay for surplus power and higher fuel use but I'm also aware that it may not be worth downsizing from a Sport-Jet due to availability and little or no savings on cost.
     
  2. Akgramps
    Joined: Aug 2008
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    Location: Alaska

    Akgramps Junior Member

    Mercury use to offer a 175 HP in their sport jet and maybe still do, I cant help but wonder why go with a inboard on a 16 foot boat unless you plan to run whitewater?
     
  3. redtech
    Joined: Feb 2007
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    Location: suger pine, ca

    redtech Senior Member

    unless you're willing to add wieght to boat the sportjet package is about the best you can do the other option would be an outboard jet and that's not gong to make you very happy i'm guessing
     
  4. yungcow
    Joined: Sep 2008
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    Location: Canada

    yungcow New Member

    That's the info I was looking for. Thanks. I knew there was something available around 80 HP but I couldn't find any details. If the sport-jet is the best deal when considering weight and cost, I'll forget about looking for something with less power.
    I wanted to go with an inboard because I had figured on needing about 60 - 70 HP in outboard power and that meant a lot of weight and a higher center of gravity. This fact concerned me a little for safety in manoeuverabilty. There are two places on my river where the current cuts a deep, narrow channel in a 90 degree turn which tends to pin boats against the bank allowing water to flow over the gunwhale. In such a case, I figured having the engine weight inboard would not allow the boat to be swamped as readily as an outboard would.
    I'd appreciate your further comments, please.
    PS The river I'm talking about has only been navigated so far by 24 foot canoes with 9-1/2s on them and those 90 degree turns are deadly at low water. These days, low water is more often than not and that's why I'm looking at a flat bottom jet boat as possibly the 'new' mode of transport.
     
  5. jbm
    Joined: Nov 2008
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    Location: montana

    jbm Junior Member

    small shallow jet

    you can check out this shallow running small inboard jet . there small lite and run very shallow water . www.jetboatsofmontana.com
     
  6. Eric Sponberg
    Joined: Dec 2001
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    Location: On board Corroboree

    Eric Sponberg Senior Member

    Neat stuff--which jet pump do they use on the Montana jets? It was not stated on their website.

    Eric
     
  7. jbm
    Joined: Nov 2008
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    Location: montana

    jbm Junior Member

    shallow jet

    we use 2 jets, jbm jet in the 80 hp 2 stroke and custom made scott jet in the 150 hp 4 stroke. you can reach us at 1-406-677-4242 thanks bill
     
  8. marshmat
    Joined: Apr 2005
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    Location: Ontario

    marshmat Senior Member

    I'd be curious to see some more photos of the pumps you mention, jbm. I don't imagine the efficiency is that great but it looks like you've managed to get virtually the entire pump inside the hull.... should hold up much better than an Aggressor or American Turbine pump when you hit something, which these boats always seem to do.

    Other than the Merc SportJet or (shiver) jet outboards, the only pump that comes to mind for use in the 40-200 hp range is the Aggressor 7000 Junior.... http://www.aggressorjets.com/drives.html and really intended more for high-speed applications than for river running. I'd be afraid of knocking the turning fin, or maybe half the nozzle, off the back if you hit a rock.

    Unless, that is, you want to cut the guts out of a jet ski, which can work but more often than not seems to end up a total hack job....
     
  9. jbm
    Joined: Nov 2008
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    Location: montana

    jbm Junior Member

    we use a jbm pump for the 80 hp 2 stroke and a scott jet www.scottwaterjet.com for the 150 hp 4 stroke. these are very efficient and the best pumps on the market for shallow river running like we do here in montana , alaska and parts of canada.you can reach me 1-406-677-4242 thanks bill.
     
  10. Eric Sponberg
    Joined: Dec 2001
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    Location: On board Corroboree

    Eric Sponberg Senior Member

    jbm, I went to the Scott site but could not find any information on the input power that their jets use. Same for your jbm jet on your site. What are the power ranges that these jets accept? Do you or they (Scott) have power curves for these jets? This is important because a lot of people are interested in jets below the apparent threshold power of about 250 to 300 HP that can be found most everywhere else.

    Thanks,

    Eric
     

  11. jbm
    Joined: Nov 2008
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    Location: montana

    jbm Junior Member

    eric do you have a contact #? or you can contact us here at jbm boats for all info on the jet pumps we use thanks bill 1-406-677-4242
     
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