SUBJECT: # 19282: Jet Drive Outboard

Submitted by Gers (63.253.95.69) from NEW JERSEY on 3/10/2001 11:53:00 AM

What are the pros & cons for a jet drive ob? I would be using it on the Delaware River which has many rocks and shallow areas. My thought is that it may be a benifit not having a prop. I would appreciate any thoughts or experiances with a jet drive, or is this a bad idea? thanks

1. 3/10/2001 4:06:00 PM Submitted by Karl (152.163.213.207) from MASSACHUSETTS says Jet outboard
   I am familiar with the specs of merc jets and there is a horse power/ efficiency penalty. The 25 prop is derated to 20 hp. The 200 becomes 140. If this is a good safety trade off for you go for it.

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2. 3/10/2001 9:31:00 PM Submitted by Sal from CALIFORNIA says Companies advertize not enough hp lose.
   Karl is close on the 200 hp, but the 25 is really about a 15 hp from prop to jet. You loose about 35 - 40 % of the hp by going from prop to jet, even if the companies that sell them say you loose less. Keep in mind, your outboard [ jet ] must be run at far higher rpms in order to function at all. This means, more break downs & far less engine life, & "LOTS & LOTS" more fuel. Sal

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3. 3/11/2001 12:53:00 AM Submitted by Dunk from NEW JERSEY says Yes, Jet's...
   Gers, you should figure on the HP loss. But you should also take a ride in a jet powered outboard before you commit. I think Sal in kinda understating the rpm thing. If a 30hp prop engine planes the boat at 3000rpms you'll need 4000-4200 to see the same out of a 30hp rated jet. The only real way around this is with HP. I mean if you want 30hp prop performance buy a 50-60hp jet.

   I'm kinda interested in where on the Delaware you are running. The Antique Outboard Club guy's run these deal called "run what you brung" days. Its local guys that can go for runs on a day or two notice in the early/late part of the season when the weather isn't predictable. Anyway they are talking about a run from Lambertville up to Easton next month.(30 mile run each way, I think) There are no jet's in this crowd, but the guy that is putting it together says with the spring run off there's plenty of water. I haven't been on that part of the river since Boy Scout canoe days, but that was late summer then and I remember there's noway a prop boat is going up that rock infested waterway. I really don't want to be feeding my 50+year gearcases any terra firma on the boat ride.

   Where are you at and do you know the piece of the river I mentioned?? Dunk

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4. 3/11/2001 8:16:00 PM Submitted by jtpbasser (206.107.124.158) from TENNESSEE says Jet Drive
   We've used jet drives on the rivers here for several years and they are great for going where no other boats can go. We hunt/fish smaller rivers and run a 16' aluminum tunnel hull boat with a 60hp Mercury jet drive. The boat will do approximiately 30mph on the water and drafts at plane in about 4" of water. We've videotaped the boat running across sand bars while someone stands on the bar... the water is at the top of the persons feet (4") and the boat sails past. The major difference with the jet is you have to allow for room to get the boat on plane due to less torque on takeoff and the steering is a little skittish. Also you have limited reverse so you have to plan your stops well. Overall it's been the best thing to happen to our river runnin'!!! Regarding the rocks - we've set up boats with tunnel hulls and on flatbotom boats with standard transom. On the tunnel hull the boat will drag or hit with little chance of hitting the intake on the jetdrive. On flat bottoms you have to be more careful in that the intake will stick down in the water about 2" and have seen several intakes broken off on rocks in less that 4-6" of water depending on the boat. One other factor is to set up the boat so it plane out level and the transom isn't sitting too low in the water.

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5. 3/12/2001 4:58:00 PM Submitted by Dunk from NEW JERSEY says Tunnels??
   JT, I'm sure you know more about this than I, but with a tunnel aren't you running the chance you could run over something dead center? Doesn't this leave the jet drive kinda hanging in the middle with nothing in front of it?

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6. 3/12/2001 7:07:00 PM Submitted by Gers (63.253.94.221) from NEW JERSEY says Thanks guys
   I appreciate all your thoughtful and informative responces. I was unaware of such a large decreese in efficiency when going to a jet drive.

   Dunk, I am only considering boating on the Delaware, because,I have always wanted to fish it. As of now my only knowledge is from the shore line. I know there is a wing dam between Lambertville and Easton but the water level in the spring should be adequate. I have a 25 foot Tiara with a 200hp Evinrude and have fished the Sandyhook area for m-a-n-y years. So this freshwater thing is new to me and I am trying to get as much info as possible.

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7. 4/30/2003 10:20:00 AM Submitted by sarah (164.156.226.84) from PENNSYLVANIA says Yes to jet drive!
   if your going to be in a shallow rocky river then a jet drive is definetly a better way to go. you can run through 4 inches of water w/o damaging anything. who cares if you burn more gas, i would rather be wasting gas then getting a new prop for a hundred dollars every month. we are on the susquehanna river and where we're at a jet is a must. you are pretty much staying at home if you have a prop in the summer time. and big deal about the horsepower thing, just buy a bigger one then. another good thing about the jet is that you can spray your freinds from 50 yards away with a wall of water that will knock them out of their boats! also, our 40/30 mercury was stolen off the back of our boat while sitting in our yard, so we are looking for a new one, but why are they so hard to find!? and why are they so expensive too!? well, thats from a girls point of view, thanks for listening. -Sarah

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