Looking to get a jet n have a few simple questions??

[ndthwacker]

Hey all i am new to jet motors and would love/ need one. I was just wondering if a jet motor will suck more gas then the same motor with a prop? And also what would be a good 60hp motor to get to convert to a jet? im not looking to new here somewhere around a 1990 or so 2 stroke?
Thanks for ur time, n i really really need a jet every boat i see with one i get to jelous then mad i dont have one.

 

[Seth]

I've always heard they do use more fuel. I know that during a recent tourney we ran a bit over 40 miles and I figured it up to be about 3-3.5 mpg with my 115/80 Etec. That was running hard and idling around trolling the whole time. Not sure how that compares to a a prop boat.

 

[Lil' Blue Rude]

Best 60hp is a 86-01 OMC Johnson/Evinrude 3cylinder 56cubic inch motor. Great motors. Make sure it's the 56cube because they made a 49cube model until 88. These OMC's have the most torque for motors in there size so they do great on a jet pump.

 

[fender66]

Yes...they suck more gas. #-o

Mine really does. #-o #-o

 

[Brian J]

IMO, the answer to fuel consumption is yes and no. Your mpg will be less because you are losing 1/3 of your horsepower in the conversion process and therefore aren't travelling as fast. However the gallons per hour will be the same. Your engine will burn the same amount of fuel at 5500 rpms whether the lower unit is a jet or a prop. You're just not going to get there as quickly with the jet.

Seth, I am shocked that your e-tec isn't more effecient. That is about what a buddy of mine gets out of his 115/80 carb Mercury. I always heard that the direct injection engines were getting 5mpg or better.

 

[fender66]

However the gallons per hour will be the same

Agree....Gallons per Hour will be the same (assuming same load on a jet vs. prop)...however...Miles per Gallon will not. A jet will be much less miles.

 

[S&MFISH]

Who Actually gauges their runs by hours? I always gauge my runs,be it on the river or a lake,by miles. I NEVER say "Well,I'm going 30minutes upstream today. Or "Let's run 1.5hrs down the lake today". It's always miles,so gallons per hour don't mean squat to me. That's my take on the subject.

 

[Ranchero50]

Yeah that, I guage my runs by minutes because running wide open (@48mph) I have 45 minutes of fuel in the nine gallon tank... 85hp Rotax (Seadoo) 717cc 2 stroke 2 cylinder with a 145mm axial jet.

The biggest thing I've noticed is the jet needs all the efficiency it can get, run the wear ring as tight as possible without loading the engine and smooth all the burrs and hard curves in the pump. Use a rubber flap between the hull and intake to help keep air out as well.

Jamie

 

[S&MFISH]

That seems logical Ranch. For my part, I have a fuel gauge and I never go further than half of the fuel I start with. That way I know I have enough to get back.

 

[Seth]

IMO, the answer to fuel consumption is yes and no. Your mpg will be less because you are losing 1/3 of your horsepower in the conversion process and therefore aren't travelling as fast. However the gallons per hour will be the same. Your engine will burn the same amount of fuel at 5500 rpms whether the lower unit is a jet or a prop. You're just not going to get there as quickly with the jet.

Seth, I am shocked that your e-tec isn't more effecient. That is about what a buddy of mine gets out of his 115/80 carb Mercury. I always heard that the direct injection engines were getting 5mpg or better.

It was about the worst possible conditions for running a jet also. The water was very rough and we were cavitation quite a bit. I'm sure this is about the worst I will get. If the water is smooth and I don't run WOT all the time, I'll get a few mpg better most likely. This was the first time I filled the tank full and kept track of my economy though.

 

[fender66]

Use a rubber flap between the hull and intake to help keep air out as well.

I'd like to see a picture or two of this if possible.