Has anyone tried the Jetpac outboard diesel waterjet?

[stevens]

I read an article last year about this new product:<br /><br />www.jetpac.us<br /><br />It's the first combination of outboard, diesel & waterjet, and supposedly works really well. If it does, how come it is not causing a greater stir in the market?<br /><br />Have any of you seen or tried this? Any views?

 

[stevens]

Re: Has anyone tried the Jetpac outboard diesel waterjet?

* bump *<br /><br />Does the lack of views mean that none of you have tried or seen it? That doesn't bode well for that company!<br /><br />How about waterjets in general? How do they stack up against regular outboards?

 

[gutshot grouper]

Re: Has anyone tried the Jetpac outboard diesel waterjet?

Looks as if they are thinking out of the box, even the 150 hp diesel weighs 900+ pounds although they claim the engune housing provides 250-500 pounds of bouyancy, I am afraid most of the boats i would clasify as regular production would not stand the additional stresses of this contraption hanging off the transom. Also, I have been on a 110 foot aluminum boat off Massachusetts and it performed pretty well with three 2000hp Detroit diesel jet drives, dispelling my former belief that they were very inefficient.

 

[stevens]

Re: Has anyone tried the Jetpac outboard diesel waterjet?

I agree that 900 pounds sounds like a lot. However, 900 minus 250-500 pounds of buoyancy would be less than the 650 pounds I currently carry on my boat (1,7L 120HP Cummins-Mercruiser Turbodiesel with an Alpha-drive).<br /><br />Even a Yamaha 4-stroke 150 HP outboard would be about 470 pounds.<br /><br />So, if the boat is designed to carry an outboard, and the Jetpac-box really delivers that kind of buoyancy, it does weight-wise seem feasible.<br /><br />It wouldn't have hurt though, for them to have picked a lighter motor...<br /><br />I do like the thought of an outboard diesel.<br /><br />I have barely even seen a waterjet over here, in a screaming water scooter. Are waterjets inherently less effective than propellers? And are noise levels and vibrations worse than with propeller drives?

 

[umblecumbuz]

Re: Has anyone tried the Jetpac outboard diesel waterjet?

The buoyancy negates much of the weight of the engine only when the boat's in the water.<br /><br />I can see two immediate snags. First, with all that weight hanging off the transom, what will it do to the boat and the balance of the rig when you're towing?<br /><br />And second, many of us go fast. That means we leave the water and crash down again, either wave jumping or when crossing the wake of another boat. That's a hell of a strain on the boat when you hit the water with all that extra weight!

 

[stevens]

Re: Has anyone tried the Jetpac outboard diesel waterjet?

Hadn't thought of towing or being airborne... Good point!

 

[tomatolord]

Re: Has anyone tried the Jetpac outboard diesel waterjet?

stillfishing - when was the last time you had your entire boat airborne?<br /><br />In the 20 years of boating I have never had any boat that I was on or in airborne to the motor.<br /><br />As far as towing goes - it might change the dynamics of the weight distribution - but that is something I bet the jet mfg's have considered and would have some recomendations.<br /><br />It probably gets little attention because the big engine companies have most of the MFG's tied up, there was only that one key west boat mfg that made a boat specifically for that engine combo. <br /><br />One of the biggest hinderances to new technology in the fields is who fixes it when you are in the boonies - spare parts etc<br /><br />it does seem like a nice niche product.

 

[stevens]

Re: Has anyone tried the Jetpac outboard diesel waterjet?

I just discovered at boatdiesel.com that Cummins Mercruiser have just launched a jet version of my exact engine:<br /><br />

<br /><br />Here's a link to the article (hope that's OK):<br /><br /> http://boatdiesel.com/News/NPageDetail.cfm?UF=1&P=20050525_CumminsMercruiser.cfm&Y=2005 <br /><br />Don't know the weight of this package, but it must be a lot less than 900 pounds, and it is sitting inside the hull.<br /><br />Now, that has got to be a Jetpac-beater!

 

[umblecumbuz]

Re: Has anyone tried the Jetpac outboard diesel waterjet?

Hi Tomatolord,<br /><br />Don't want to start a 'let's see who can fly' discussion, but my boat leaves the water often. Quite probably the stern and prop are still in the sea, but the motor howls each time we deliberately go yumping.<br /><br />The point I was making really was that the jarring at the transom in rough conditions must be greater with a heavier outboard motor package, and there are bound to be occasions - especially offshore - when the whole weight is taken on the transom.<br /><br />I've always thought that hanging a huge lump of metal over the stern of a boat is daft - especially when it dies in a following and breaking sea. Having said that, I love outboards for all the other great reasons!

 

[bmtsa2003]

Re: Has anyone tried the Jetpac outboard diesel waterjet?

I have filld out countles request forms concerning the jetpac never received a reply. What a waste of time. Could not find anyone who has experience with this system neither. Their site is touting the design award and promises new engine options since about 18 months now.