i am looking to buy this 2003 g3 1756 center console boat. It comes without a motor and i have a mercury xr6 150. So i wanted to know if it something that is possible to do and not sink the boat when i put it in the water.
thanks for the help!!!
What is it rated for?
From what I’m seeing is max 70hp.
There should be a plate riveted inside the hull near the transom stating the max horsepower per Coast Guard specs. Do not exceed that at your peril. If you don’t have immediate access to the boat in question, ask the seller to send you a photo of the plate. Your insurance will be invalid if you exceed the maximum horsepower and in case of a catastrophe, you will be solely responsible for any damages, including death of a passenger.
There should be a plate riveted inside the hull near the transom stating the max horsepower per Coast Guard specs. Do not exceed that at your peril. If you don’t have immediate access to the boat in question, ask the seller to send you a photo of the plate. Your insurance will be invalid if you exceed the maximum horsepower and in case of a catastrophe, you will be solely responsible for any damages, including death of a passenger.
He’s right. If that boat is indeed rated for a 70 hp max, if you exceed it you not only risk the integrity of the hull, transom, etc but you also void any insurance policy should you need it.
He’s right. If that boat is indeed rated for a 70 hp max, if you exceed it you not only risk the integrity of the hull, transom, etc but you also void any insurance policy should you need it.
not to mention its just not safe in general
There are plenty of jon boats running around in Missouri with 250-300 hp outboards. Is it a great idea probably not but I bet it sure would be a good time.
Awesome Beads, just awesome! 
There are plenty of jon boats running around in Missouri with 250-300 hp outboards. Is it a great idea probably not but I bet it sure would be a good time.
Not necessarily the brightest logic. Just because you can, doesn’t mean you should.
You’d have to be pretty stupid to put a motor that is twice the size of the recommended max HP on a boat. Especially on a jon boat. Not like we’re talking about upgrading from a 5 to a 10 hp motor here. My Grandfather would have called it sh** for brains if he were still with us today.
Nothing like an 800 lb boat with 500 lbs of engine!
What is it rated for?
SPECIFICATIONS
Dry Weight 865
Package Weight 1590
Width on Trailer 83″
Boat Length 17′ 2″
Package Length 21′ 8″
Max Horsepower 75
Fuel Capacity 19 G.
Person Capacity 4
Beam 83″
If you do this, make sure to take a video and report back! 
-J.
Practice this “here hold my beer” 
The great Chris Rock used to say
“you could drive your car with your feet if you want to but that don’t make it a good idea”.
I think you got your answer here tho. I got a 150 on my 17’8 dominator and that is pushing it. I don’t think I have ever pinned my shifter all the way?
Oh to be young and fearless again !!!
I had a 18ft Polarcraft johnboat many years ago, I put a Merc 50 on it that had been bored thirty thousandths oversize and put 75hp carbs on it, changed the timing blah blah blah.
The CO that caught me running full bore on the Iowa river was not impressed and I got my butt chewed royally.
Oh to be young and fearless again !!!
I had a 18ft Polarcraft johnboat many years ago, I put a Merc 50 on it that had been bored thirty thousandths oversize and put 75hp carbs on it, changed the timing blah blah blah.
The CO that caught me running full bore on the Iowa river was not impressed and I got my butt chewed royally.
No doubt, he was jealous.
Convert that 150 to a jet and its actually a legit setup.
But no I wouldn’t reccomend putting a propped engine of that size on that rig….
Convert that 150 to a jet and its actually a legit setup.
But no I wouldn’t reccomend putting a propped engine of that size on that rig….
Still over 70 hp according to Yamaha specs.
JET DRIVE 150 hp
Our 2.7-liter F150 Jet Drive four stroke produces 105 hp at the pump. It features a DOHC, 16-valve design with four valves per cylinder and long tube intake tracks. This produces ample power for navigating shallow, rocky water.
<div class=”d4p-bbt-quote-title”>Drizzy Musky wrote:</div>
Convert that 150 to a jet and its actually a legit setup.But no I wouldn’t reccomend putting a propped engine of that size on that rig….
Still over 70 hp according to Yamaha specs.
JET DRIVE 150 hp
Our 2.7-liter F150 Jet Drive four stroke produces 105 hp at the pump. It features a DOHC, 16-valve design with four valves per cylinder and long tube intake tracks. This produces ample power for navigating shallow, rocky water.
I’m fully aware. I’ve done it, doesn’t really give you stupid crazy top end speed but man is it nice to be able to jump on plane with 5 dudes in the boat, coolers, gear etc….and still sip the fuel.
I had an XR6, was a good motor. Ran fast. I would NOT put this motor on the hull you are asking about.
I’m fully aware.
How does 105hp at the pump make it legit when the hull is rated 70hp max. ANYTHING over 70hp is NOT legit.
conforming to the rules; legal.
“is this motor legit?”
To clarify its a SeaArk MVJT 1872 that this mod was done to and it required a significant amount of time with a boat builder and very talented aluminum welder. A much stouter hull than the g3, that required transom and stringer rebuild/design. The engine was a Honda BF150>105 at the jet.
Really when scoping a jet like that you aren’t seeking top end, theres literally only so much water the jet impeller can suck and this limits you from coming unglued (like you see with way over powered outboards with props). I should add running a tunnel hull jet at any speed over 23-25 knots is not comfortable or really what that particular set up is meant to do.
It’s a significant undertaking that requires the time and attention of a certified builder. I totally agree that one should not just willy nilly slap larger engines on boats that the hull isnt rated for. I am also a strong advocate of putting the maximum hp that the boat is rated for, makes life easier. But what the OP is describing is a very bad idea, in all seriousness he should flip the engine and use the proceeds to buy a Honda or Yamaha 70………..if you can find one.
jet drive would be fun. yea i ended up not doing it. thanks for all the reply’s. i know that the motor would go on it but i just did not want to sink the boat. because like someone said the boat is like 800 pounds and the motor weights in at 400 and then add like full tank of gas and then two people. does not look good lol.
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