DuraJet v. Traditional Jet Drive
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Hey guys –
Anyone know anything about this DuraJet company making what looks to be a prop housing?
http://www.premiermarine.us/durajet-jet.php
Supposedly it achieves jet-like features (shielding the prop from rocks, primarily) without the disadvantages of a traditional jet drive. I’m kind of intrigued.
Zach
Here’s a two tone version showing the new lower unit. I think this is a minimum 20 HP system, so it might not work for small Gheenoes, but I bet it’d push a Hog Island Skiff…
I have seen them used in military applications on Zodiacs, with this military spec Evinrude that can run on gas, kerosene, and diesel. I think you would lose the super shallow capabilities of a regular jet though. That thing looks like it it would have to hang down a little further. I think its its hard to beat a well designed tunnel hull paired with a jack plated jet.
WOW, did you see that the only starting method was pull start? Pull start on a 55!! Takes a man with a big arm to start that motor!
When the going gets tough, the tough go fishing.
It gives no advantages to running in shallow water. I’d damage that housing in no time in the 4-6″ water I’m running. The only advantage I see is that if you had a prop motor and you did not want the hassle of getting a traditional jet foot conversion kit, where you would have to raise the motor for the intake.
Travis that’s interesting. Could you elaborate? Is it because the water intake is in-line instead of below the jet output?
55hp pull start would be pretty rough. Bout like starting a lawn tractor…
Zach
Wouldn’t even remotely consider it for any application. It’s not a jet and it’s not a prop. The only advantage I see is it’s safe to swim around, if your into that sort of thing.
Sorry to respond a couple weeks late….
The Durajet offers no depth/draft advantages due to the fin of the lower unit still extending down several inches below the transom. Unless it could truly hold up to heavy impact, I don’t see a major shallow water advantage other than prop protection.The jet foot intakes on typical jetboats extend 1-2″ max lower than the transom to suck the water upward into the impeller. And the Super jets with tunnels and recessed intakes can blast over dry rocks.
An alternative to protect the Lower unit on a prop outboard is to add a “Rock hopper” skid frame to protect the prop. I’ve got this on my Yamaha 25hp on the SeaArk. It drafts 6-8″ on plane (when I have it levered upward at an angle). I keep the tiller motor unlocked, so when I hit a rock… The motor just raises up in my hand. It scares you pretty good when you strike bottom, but the prop has made it through some bumpy shoals.
Now for the tiller jetfoot. I have tested the limits In my first year of ownership, and have put the HogIsland into some sketchy water. Zig-zagging up rocky shoals…cutting off the throttle and pushing down to raise the motor as I hit the unavoidable ledge—saving the motor impact.
A couple of shallow 1-2″ ledges hit at topspeed in flat water have finally cracked the intake jetfoot. So I have now hired a welder to help me stitch together a crack, and add back two silverdollar sized chunks.
I have heard plenty of rumors about UHMW plastic jetfoot a becoming available….and I will definitely buy the first one I can find. Two CNC CADCAM machinists in PA make or have made them…but the only guy who custom milled these doesn’t make them anymore. Evidently a large sheet of that stuff costs over $15k.
His small business barely covered the cost of one sheet over a couple years of making intakes. The other company is Rockproof. They make an excellent intake out of the durable plastic…but it’s only designed for large outboards.I’ll let you know when I find a better alternative for shallow, rocky rivers. So far, I love the boat and its capabilities.
Travis, I’ve enjoyed following your adventures in the new boat when you post them on here.
That’s a pretty beat up intake foot – does it seem to take all of the abuse or does it pass it on to the rest of the motor? I recall you have a 40/30 yamaha, do you have a “shallow water” switch you can flip, where the motor can kick up if it hits things? Ever use it?I have a little used aluminum jon I got over the winter with a Merc 25/20 jet I’ve been running a little bit, still getting used to it.
Ever think of using “side skirts” as shown about 1/2 way down the page here:
http://www.leeroysramblings.com/outboard_jet_maintenance.htm
Thanks,
MikeHey Mike….no shallow water kick up setting, just a propped up locked setting to keep the jetfoot clear off the water. I run with the motor unlocked, that way, if I encounter a collision with the bottom, the motor kicks up. The Yamaha tiller is nice in that the weight of the 220 lb motor is offset by a Nitro-tilt assist that acts like a shock absorber, allowing the engine to fall back slowly, and lift with more ease.
So far, there is no observed damage to the body of the motor nor the transom. I’ve just got some nice gouges I’m the plastic to melt back smooth when I find some time.
Mike, I’d be reluctant for side skirts or even a cavitation plate for the rocks I’m bumping. I’d probably knocke them off in a couple trips. If your on more gravel and flat water, they’d probably be a good bet.
Here’s the repaired foot back today. The welder called me and said it would cost $45. I gave him $60 and still feel like I underpaid him. On the way out…he said they do milling, and he may be able to make me a UHMW foot.
I sure hope he can. Until then, I’m stoked with this incredible repair. He even removed the grates and hammered them out flat.
That looks like some really nice work, I hope it works as good as new. What an improvement.
My 25/20 is a two-stroke and only weighs 124 pounds, per the manufacture’s sticker on the side of the motor. It is however fairly loud and doesn’t seem to get killer mileage.
My next challenge is to rebuild the tiller handle with new bushings, apparently this is a common problem for 10-15 year old mercury of this size, the plastic just crumbles away after a decade or so. Should tighten up the steering response quite a bit.
I don’t have near as tough of a hull as you do, and I am trying to keep it on some tamer rivers around here, mostly for stripes and carp. I’m not sure if this is the ideal set up, but I got a pretty good deal on it, and it has run really well on the few shake down trips I’ve taken it out on.
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