Conversion of Jet to Stern Drive

Discussion in 'Jet Drives' started by Suggly, Nov 20, 2012.

  1. Suggly
    Joined: Sep 2012
    Posts: 4
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    Location: Australia

    Suggly New Member

    Suggly is 21ft plate alloy & has a jet that blocks with ribbon weed in the lake; has anyone converted from Jet to Stern Drive using the same inboard engine that ran the Jet Drive??

    Engine is a Hino Diesel about 150hp. Bloody noisy to boot.

    If yes, how did top end speed change, I get 21 knots from jet (until it blocks and drops off the plane).

  2. tunnels

    tunnels Previous Member

    It would be a whole new installation !! remove jet and block up the holes one in the bottom and one at the back beef up the transom and mount the sterndrive your motor could go back to mate up close to the sterndrive or leave it where it is !! If you fit a jack shaft made the right length with 2 universals (one sliding ) the motor could stay where it is so nothing has to be changed and it wont upset the ballance of the boat !!.
    The jet unit and the stern drive must be pretty close to the same weight .
    Top speed dont know and would say it could be a couple of knots slower BUT the lower end of the scale the motor is much more usable in the lower rpms and could be a bonus of getting more miles per litre !!.
    Jets are either flat out or slow the inbetween there nothing .
    I would seriously look at the newer sterndrive with a jet prop exhaust goes out the back underwater . If you engine room hasent got any sound insulation then you need some like every where including under the floors hull sides and hatch etc . Also look at the motor mount situation and fit some big mounts and kill the transfer of engine noise that could be reverbirating through the hull !!.
    The HINO is a 4 cylinder or a 6 ?? it will be a heavy mother i would say ,150 is what a small modern engine puts out !! The Hyundai vee 6 is 240 hp and is quite small and really smooth running and quiet .It comes with a mercruiser sterndrive all as one unit . there is also a 170 hp unit as well get on the sight i just sent and look down the list and see whats there . they have agents all over so have to go looking .
    Time for a clip board and a new pen and do some checking on weights and hp and what will it all cost ?? and the end result will be ?????
    I spentime working in a fibreglass boat building company in South Korea and the hyundai plant was just over the fence so to speak ,we made a pair if 22 foot fishing boats one had the 250hp motor the other the 170 hp standing in either boat the only way you could tell the motors were idling was to look at the tachometers they were so quiet !! The young Korean engineer i worked with and myself help develop the sterndrive units inconjunction with the Hyundai engineers !!. :);):p:D:p
  3. marshmat
    Joined: Apr 2005
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    Location: Ontario

    marshmat Senior Member

    Jets tend to be optimized for ~25 to ~65 knots, and (speaking in very general terms) are usually outperformed by propellers below that range.

    There's no guarantee that a sterndrive will solve your weed blocking problem. I've been on many a lake where the weeds get wrapped up in balls around the leg of an outboard or sterndrive, requiring a bit of reverse thrust to clear.

  4. magny7
    Joined: Jan 2010
    Posts: 33
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    Location: Surabaya

    magny7 Junior Member

    If there's too many weed in your water, you might want to consider Florida type swamp boat
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