I have a 90hp merc that I am considering converting to jet drive. I have heard some bad things on the jets recently since I have been checking into them, like the horsepower decrease and that they use alot more gas. Can anyone tell me if you see that much difference in the gas usage? The company I have been considering dealing with is in CA. Does anyone know of any other aftermarket dealers on the east coast?

what's the name of the company in CA? I have a 50 hp merc that the lower unit needs replacing. I've had no luck finding a rebuilt one. The only one I've found is in the $1500 range. My motor runs great. Can I convert it to a jet? The boat it is on drafts about 6 inches of water so a jet might be good. I know Leo on the Virginia striper web site runs a jet. Might try posting there.

The professional fishery people and commercial fishermen I know here on the coast will tell you that a jet will 'spin the gibblets' out of most any outboard in a relatively short while.They run at a much higher RPM to achieve commensurate thrust.I would not use one unless shallow running is more important than engine longevity.The Hamilton Jet is a unit designed for inboard/outboard installation and is a wonderful product,BUT not on outboard motors.Fuel consumption is,as Blue states,higher in the outboard application.Hope this helps.I have seen few,if any jets on 4-STROKE outboards;this may be a factor of lower RPM--anyone know more about this aspect?

Efficiency. A jet drive is not as efficient a delivering thrust. Think automatic vs straight drive in the earlier days of automatic transmisions on cars. If you look at factory outboard jet drives you may have a 90hp powerhead delivering 60hp with the jetdrive.

Bluejay,

I have run jets on the upper Potomac and Susquehanna rivers for years. The set up for optimum performance is a jet on a stick steer shallow draft boat (Xpress 17' my favorite). You sit up front with your trolling motor batteries and gas tank and that weight distribution keeps you level and as shallow as you can get. You loose 1/3 of your hp. So a 90hp block with a jet = 65hp. yes fuel consumption will be more. If you are planning on primarly using your boat on Buggs it would not be the best choice because of waves. Not saying you can't you will not be very efficient when the wind and boat traffic gets up. Primary use for a jet is shallow water when a prop can't cut it. Good fishing, Doug

I believe Honda makes a jetprop motor.

Outboard specialties in Cali. is the only company that makes jet foots for outboards. They own the patent. With a jet outboard you do lose hp and it takes more gas. Also it is very important that the bottom of the jet be even with the bottom of your boat. That reduces drag and improves performance. I only recomend a jet if you travel in shallow water on a regular basis. Hope this helps

Thanks for the input everyone. The company I was reffering to is Outboardjets.com in san leandro CA. They make jet lower units for just about any motor. A friend of mine just ordered one for a 40hp that he converted to a jet and he loves it but his boat is much smaller than mine. I fish the lake and river but we also fish the lower james from richmond to surry so gas usage is also a factor. Just the thought of streching out the river a little more would be nice when the water gets skinny. Thanks Bluejay

Bluejay....as an estimate, take the fuel consumption you get now with a prop and plan to have 25% worse fuel consumption (mileage) same motor with a jet. The decrease comes from the outboard jet having to turn the water rather than straight thru. The 25% will get you in the ballpark so you can decide...you may get a bit better or worse. Also, remember that your upstream speed will be cut by 25% as well so plan those extra minutes into your fuel mileage....good luck and let us know...jfo

Thanks for the info Joe. I didn't know the fuel efficiency was that bad on jets. I guess most of the time you wouldn't normally run a jet that far. But with the gas prices as they are every little bit helps. Buggs probably would not be that bad as we don't normally run very long distances but the lower James is a different story. One thing some may want to consider is a hydraulic jack plate. I put one on a couple years ago(power lift) and once I get up on plane headed up river, I raise my motor as high as I can go without sucking air. I have'nt had to use it yet but I guess I'll stick to the spare prop and wrench routine. Last trip down cought some flats up to 40# up dan be back Sat.

You may want to call or email
800) 349-2628 ... (504) 888-2798 ... Fax (504) 888-2881
E-Mail to: (dmarine@rodnreel.com)
I have got very good prices and service from them on boat and motor parts.

The bottom line is that the outboard must reverse the waterflow after it enters the pressure pump before spitting it thru the impeller and out the jet. This reversal of direction is what causes the HP rating decrease (powerhead vs pump HP) and the fuel efficiency hit. Inboard jets are much heavier and the sportjets take up inside the boat space and are generally louder but they don't suffer the same power loss because the water flows straight thru. Hey, the jets are great at what they do which is to add confidence running skinny water but they (all of them) have some downsides against the outboard props as well. If you want a demo of a sportjet let me know. A picture is good:
http://www.riverpro-boats.com/pages/news/InFisherman_Feature.shtml

good luck...jfo

I happen to run a Regal 1700XR jet and there are definately some pros and cons.
First and for most for those that have witnessed any type of prop accident, jets will be an attrative alternative.
Mine is not like one of the Sea Doo/Yamaha water jets which are very fun but not of the boat quality of my Regal. The 1700XR is the same as the Regal 1700 only rigged with a 175 Merc Jet instead of the Volvo stern drive.
It hole shots very well, is very fast, smooth and has the handling of a jet ski at high speeds. Very fun boat.
It burns A LOT of fuel and is very difficult to control at low speed.
But it was worth the sacrifice for the need of only 14" of water and the lower maintenance costs along with the obvious safety issues.
I prefer a prop but momma says no. She scared of props.

I almost went with a jet drive because of Falls Lake, I was afraid I'd tear up a prop crappie fishing. I actually did tear up a prop last year, but it was because somebody had parked a Lexus in the lake at the ramp. Props ain't so bad. I've been hurt several times on the trolling motor prop and never once on the gas powered one.

I converted my 135 Mariner to a jet ordered from Outboard Jets in CA. I put it on a 2004 20' Grizzly Tracker. I love mine, but there are many things you need to consider.

I found some articles on the web that were really good help in my decision to go with a jet.

I'll look and see if I can find them again and post the links here if I do.

I used a manual jack plate + a 5 inch Transom vertical extension both from www.cook-mfg.com to get the 6-8 inch increase in height required for the jet intake to be level with the bottom.

If I wasnt going to run in skinny water, I would stick with a prop. Jets are good for what they do run skinny water, but they are harder to steer and less efficient.

Monsterbuk

Here is a link to some info on jets if you are considering a jet purchase. I found it helpful when I decided to purchase my jet lower unit.

http://www.sonarsearch.com/Jets.htm

Monsterbuk