Jet boat fuel gallons/hour experience only please.

[emerson]

I have a 50/35 Tohatsu factory jet outboard that burns 5US gal/hr almost wide open. Pushes me at 35km/hr, 2 guys and gear, boat and motor weigh 800 empty. Dre posted his 137hp jetski motor used a 40l/hr(8.8Imp gal/hr) loaded heavy at 35km/hr ish. I've been told a 175 sport jet uses 5gal/hr, sounds too good to be true?? What are your real world numbers?

[Dre]

The current of the water makes a big difference, and how much weight you push. I doubt that the Sportjet 175 will do 5G/hr under extreme conditions. Trying to plane in fast current is like spinning your tires in the mud. The water you are trying to push off of is already moving away from you. It also has some other dynamics like shifting and rocking the boat which robs speed and wastes fuel. I burned double going up than down. My boat weighed 3500lbs fully loaded and that speed is GPS not water speed, water speed is 6-7kms faster.

[Salty]

Like Dre says it all depends on the load on the motor (weight, current etc). I'm thinking you've heard someone who's calculated 5 gal/hr with am empty boat at speed. Load it up and run it against current and uneven surface and you'd more than double that I'm sure.

[300WinMag]

I have a 5.7L Vortec with a 19.5 footer. If I am up planing with a couple of people with minimal fishing gear, I am usually doing about 30mph at 3000rpm and burn about 6 gallons an hour. It goes down from there - more weight, river current, chop if I am on a lake, etc. I considered buying a 175 Sportjet when I bought my boat and my research (online, salespeople, etc.) suggested that I would have considerably less horsepower and higher operating costs, so I went with the Vortec. My boat is not fuel injected.

[emerson]

I have a 5.7L Vortec with a 19.5 footer. If I am up planing with a couple of people with minimal fishing gear, I am usually doing about 30mph at 3000rpm and burn about 6 gallons an hour. It goes down from there - more weight, river current, chop if I am on a lake, etc. I considered buying a 175 Sportjet when I bought my boat and my research (online, salespeople, etc.) suggested that I would have considerably less horsepower and higher operating costs, so I went with the Vortec. My boat is not fuel injected.
Exactly what I was looking for. I'm aware of the difference between up and down and water and gps speeds. I use water speeds by running up and down and calculating the difference using the gps. Current is often stronger than it seems.

[Barracuda]

as long as the boat is not overloaded getting on plane upstream should not be an issue with a properly designed hull .
water speed +boat speed is how fast you are pushing the boat regardless of the actual distance traveled . If the boat planes at 20kmh has a top speed of 29kmh and the stream is going 19 then you can be on plane travelling at 1kmh with a top speed of 10 kmh but you will have a water speed of 29KMH. hull and pump design are pretty important .

[ryanb]

14.5 firefish snapper with 200 sportjet. Lightly loaded I can get 4.2gph at 35 km/h. Usually cruise at 6gph for about 42-43 kph. Heavily loaded with almost 2000lbs of gear and people I get 8 gph for about 38ish kph.

These numbers are over water. Add or subtract current for ground covered.

Bigger sportjet boats get a fair bit less mileage.

You can save a lot of fuel by learning to not fight the river going upstream and using the current to your advantage going down.

[Barracuda]

jets don't reall push off the water it is the expelled water that pushes the boat forward regardless of whether or not the jet is in the water or in the air. for every action there is an equal and opposite reaction . its the same as a fire hose. or a fan or a propeller etc . think thrust requirements

[emerson]

14.5 firefish snapper with 200 sportjet. Lightly loaded I can get 4.2gph at 35 km/h. Usually cruise at 6gph for about 42-43 kph. Heavily loaded with almost 2000lbs of gear and people I get 8 gph for about 38ish kph.

These numbers are over water. Add or subtract current for ground covered.
Bigger sportjet boats get a fair bit less mileage.

You can save a lot of fuel by learning to not fight the river going upstream and using the current to your advantage going down.

Good stuff. All goes into the "next boat discussion".

[BEAVERBRUCE]

175 sportjet I burn 6.5 gallons an hour with 900 lbs on board not counting fuel.

[browningboy]

Hit mean chicken for great feedback, all jet boaters there

[chinooker]

350 chev carburated 4bbl Hamilton 2 stage
15/gal/hr@30mph 20ft boat anyone that tells you their jet boat is getting 6g/h is full of shit!
my old boat with evenrude 90/65 was about the same. Know some guys with sport jet and optimax's they don't run 6gph either

[eric]

running a 17ft Firefish with the 175, and running up river with 4 people on board,cooler full of goodies 36 gallons of fuel,usually use about 7-8 g/h-4400 rpm-- 9-10-11, g/h when I am into the throttle.
Down stream, 6-7 g/h readings are taken through my flow meter.
would never buy another sport jet.
All aluminum 350 for my next one

[winchester284]

Have an 18 ft Harbercraft with a 200 sportjet. I installed the Mercury smart craft diagnostic gauge which is calibrated in US gph. I tend to run it at around 6gph which is about 4200rpm. I use my flow meter to guide how hard I push the throttle. On flat water with no current and 2 people in the boat, that's almost 40km/hr by gps.

This is my 8th year with this boat and I'm very happy with the sportjet would definitely buy another.

[killman]

I seem to average 7-8 for the trip that's up and back. Seems to be a lot more up than back. This isn't really loaded with 4 people. 350 4 bbl. Hamilton 2 stage.

[white moose]

Have a 19ft hammerhead. Loaded heavy with 4 guys upriver(muskwa) 20 gal an hour.

[nap]

Fuel economy and river boat/ jet boat can not be said in the same sentence that would be a double negative. Every river, every load, every trip is a little different, but on the average, 4200 to 4500 RPM with my 20 foot Omenica, 3 guys, hunting gear and food for a week averages between 7 and 9 american gallons per hour. I try not to factor speed into it, actully never do, speed usually means more fuel and f**K ups.

[Elkchaser]

Can't just rate the motor - depends on lots of factors including what it's pushing and keeping your water moving parts in optimal condition. Running a 14.5 ft/175 SJ I burn 5-6 gph on skeena during fishing season with 3 guys and day gear, always at 3700-3800 rpm. Last fall muskwa ran out 90 km on one 20 gal tank with 2 guys and two elk with 2 weeks gear, at 4000-4200 rpm. Can't keep up with big boats tho, but gets me to spots that I wouldn't have the skills to get to in a bigger/faster boat. Just the facts, take it or leave it.

[bridger]

Before I bought my jetboat sitting around the coffee shop listening to my buddies that owned riverboats one up each other I was convinced of two things: the best jet boats needed very little fuel and ran on wet grass no water required. Lol! Nice to see some realistic advice on this thread.

[kendoo]

"There's more to life than jet boat fuel milage" 2 mpg average on 22' 454 big block & pack enough fuel so I don't have to walk the river banks looking for someone else's fuel.

[Barracuda]

There are plenty of good jetboats that are good on fuel because the hull design, pump and engine combination works together.
Too many people try to solve poor hull design or overloaded boats with more engine which is a very piss poor band aid solution. Burning double the fuel which means carrying more fuel which means loss of payload and so on and so fourth.
There is a reason the smaller well designed boats are taking hold , they are getting good fuel economy able to get more places and are more use.