Heres something you don't see every day

[wired]

The 260 HP Merc had to go. Too much HP on too small a boat. Fun while it lasted though. Unstable as hell over 68 ish and the motor wasnt even waking up yet. So I sold it for a tidy profit and picked up a fresh rebuilt 150 Merc with jet drive AND a new SEI lower. I'm going to give the jet pump a shot The river here is treacherous and I keep smacking skegs and props on rocks. We'll see. Got it rigged up today and I should get it wet tomorrow.

 

[keith4216]

First, theres no such thing as to much hp. Second, what the hell is that. Have never seen such a thing, should be interesting.

 

[yellowfiero88]

Seen a few of them. Interesting setup. Don't think I've seen one on a mate before. Should have no issues with it being to fast this go around, takes more power to run a jet vs a prop..... keep us updated as to the performance and numbers you get out of it. If nothing else, swap over to the standard lower and sell the jet lower. They do bring good money

 

[DropTop5.0]

I've been looking at motors for my Enticer and I've seen these motors a few times and I've been curious. Keep us posted.

 

[Ramifications]

Coming from a propped engine, this will take some getting used to. A buddy of mine has one on his bas boat... it's great for shallow water and rocky bottoms, but handles totally different. Good luck

 

[Jimway]

" First, there is no such thing as too much HP" Well said. It does take hp to pump water but there is also nothing hanging down below the hull. Interested to see how well it goes.

 

[wired]

" First, there is no such thing as too much HP" Well said. It does take hp to pump water but there is also nothing hanging down below the hull. Interested to see how well it goes.

Yeah, well on a 125 HP rated hull that really strains past 65 mph to stay on the water it might be a wee bit on the irresponsible side to run 260 HP ( OK it was a 260 converted to 280 specs ) . Even with a 23 pitch prop that would get the RPM's down so 85 was the top speed I could feel the hull twisting on launch. Like I said. Its fun for a while . Sort of like dating a stripper or driving a 9 second car on the street. Ive done both and it gets old after a short while.


I'll get her out today. 50 MPH is what I'm hoping for. That might not be obtainable though.

 

[goingcamping]

Its fun for a while . Sort of like dating a stripper or driving a 9 second car on the street. Ive done both and it gets old after a short while.

SO true!!!

 

[mouse4x4]

keep us updated i am curious how this works if nothing else you have one heck of a squirt gun if you trim up

 

[wired]

I dropped it in the water at lunch and took the boat in to work. Preliminary reports are that I either need to remove the jackplate or position the jet up a good bit. I also need a water dam to direct flow under the motor and not directly into it.

That 150 is dead quiet. At least compared to the old 260. Take off is quite soft . It will absolutely turn on a dime at low speeds anyway. Couldn't go too fast as water is blowing off the motor and back into the boat without something to direct it around the mid section..

 

[ezstriper]

the jet drive will loose 25-30% of horsepower

 

[Jimway]

The jet pump intake will be up about level with the bottom of the hull. You will only be taking water from the 'Boundry Layer' on the surface of the water. I am very interested to hear how well it works on a Mate.

 

[wired]

Well Ive got that sucker jacked up all the way on the jack plate. The front of the water intake is about level or slightly above the pad. Had to bring it up about 3 inches from where it had been. I'll see if I can get it out after dinner.

 

[boatman4021]

Remember, level with the pad might be ok with the motor bolted straight to the transom, but with set back, it will probably need to be higher. When you get on plane, the water is only level with the pad right at the transom. From there, the water goes up and the farther back the motor is, the higher it will need to be to keep the jet from plowing.

 

[Don's89 Senator]

I think it's cool just to try something different. My hat is off to you for trying something . Might not hang with a prop but, At least you have the nerve to give it a shot.

 

[wired]

Well I have always wanted to try one and I made enough money off the sale of the 260 to pick up a complete fresh rebuilt 150 with a new in the box SEI lower without it costing me a dime more. I figured I could always sell the jet if it wasnt my thing.

Anyway the boating report. Outboard jets are very sensitive to height position. I tried a few settings after dinner and it seems to run best without splashing with the front of the pickup positioned about 1/2" below the pad. Any lower it splashes something fierce. Higher and it blows out on the slightest corners. Holeshot wasnt bad. Good enough to pull up an adult skier with myself and two kids in the boat. I would NOT want to ski behind the boat with that pump though. I was able to run it 46 MPH GPS with the current and about 42 against the current. It will turn in a spin the bottle turn at off idle but high speed cornering sucks and absolutely requires the motor be trimmed down completely . I was able to take the boat into a few areas Ive never been able to go before but about 10 inches of water is as shallow as I could go without planing the boat. I did get to hose the kids down on the shore a few times with the jet pump before the sun went down.


Will I keep the jet? Probably not. Neat gimmick but I like the higher speed of the prop and especially the higher speed cornering potential. It will likely stay there until the spring but once it warms up enough I'll swap in the propped lower.

 

[wired]

the jet drive will loose 25-30% of horsepower

Yeah. It already has . Thats why the "150" is rated at 105 HP. It runs about like a 105. I have been able to tweak it up to 47 MPH.


I usually get funny looks when I tell people I want to cut back on the HP or that I don't need to go faster. They are looking at me like I'm nuts. Heres the deal. I live on the Columbia River in the Columbia River Gorge. Thats where I go boating. Pretty much a desert here with very few other options to put the boat in. The river is rock lined in most of it and theres basalt columns sticking up in random places. Oh, and its a wind tunnel with mountains on either side and the entire volume of air passing from East of the State to the West passing through daily. 15-20 MPH or higher wind most of the time. There are usually white caps and 2-3 foot swells. There is the occasional good day but its rare that I can get to full speed and I have wiped out 2 skegs and 3 props in the last year. See where I'm going with this?


I'll likely pull the jet off just because on those 5% days I like to go fast but to be honest I'm better off keeping the jet. Good thing though is the SEI Chinese lower has a 3 year no fault warranty so I can smack it all I want and send it back every now and then to get repaired .

 

[Jimway]

Kind of reminds me of boating out of Vantage.

 

[wired]

I disconnected the idle stabilizer and retimed it to 22 degrees BTDC WOT. Picked up 2 mph and it came alive after 5K. Doesnt matter though as the jets sweet spot is 5200 and if I tilt it up it loses hold of the water. It wants to run witht he jet stream parallel to the water. To get the RPM's up I'd have to get more power on the high side. That would be a simple job actually with a set of reduced volume heads and maybe a Bobs tuner. It would help on the soft launch a lot too. I'm sure with a small amount of work I could get 50 MPH and a good launch. High speed cornering without trimming down is still not going to happen though. It is fun to drive.

 

[Bill Gohr]

When you put a jet pump on the boat, the pump needs to be as close as it can be to the boat and still turn, as well your boat will never work well with it because it is a V bottom, thats why it is so trim sensitive. The pad will protrude down below it or above it, no matter what you do, it will arrate the pump. They work the best on a flat bottom boat with the intake about 1/4" below the bottom and negative trim.

Also, when we built V6 jet pump outboards, we had to take compression out of it, not add it, on decelleration, the motor detonates so bad it sounds like it has marbles in it, if you look the OMC 105 jets have looser heads to correct this issue, one of the reasons they were called 105's.