One poroblem on the wisconsin is sucking sand into the intake and the sand eating your impellers, is this a fact or is it a prob if you go at idle speed over shallow sand? Also you had stated that your jet is converted, don’t you lose 40% HP on the conversion? 115hp to about a 60hp, how come you just did’nt buy a jet outboard instead of converting it
I am no expert but I think all jet outboards are converted. I think I read that one company in CA makes all the jet lower units. So I am not sure there is such a thing as a true jet outboard.
150hp = 105hp
115hp = 80hp
Well i know you can buy for instance a 25 merc jet so they do make’em
Right, but it is converted by somebody.
Dealer or guy at the factory or sombody.
So it all ends up the same no matter who does the conversion as far as I know, I may be wrong. Jason has done a lot of research on it.
Dan, Let me try to answer your questions. As far as sucking sand into your intake, that is a low speed mistake that would cause that. Running shallow in a jet is a running fast thing, the pressure of the hull presses the sand down, by the time the sand is loose again you are long gone. Another safeguard is a stainless impeller, which I have…it’s another $400 dollars but worth every penny, my sleeve will wear but outboard jets have a solution for this too, the impeller and sleeve are tapered and you have shims on your drive shaft, when the sleeve wears you move the shims from under the impeller to above the impeller this moves it down in the taper tightening up the tolerance back to like new. I just replace the sleeve, it’s only forty bucks…either way it’s quick and easy. The reason I did a conversion is that no one makes a turnkey 150/105 jet and that’s the size I wanted. Yamaha and mercury make turnkey jets through 115/80, and that wasn’t big enough…you can get 25/20-115/80 from merc. You lose about 30% of powerhead ratings with a jet, my brother has a 90 hp outboard on his boat with the jet conversion it’s a 65 hp so it’s called a 90/65 jet and so on.
We just re-shimmed my buddy’s jet the other day – it’s very quick and easy to do, but for some reason he hadn’t done it in about three years. We took the gap from about a quarter of an inch to 20/1000ths. I guess the book recommends 30/1000ths – which we discovered later. Anyway, his wedge insert and prop are not worn evenly (last year was sandy – the river was LOW)and the gap is right on where the impeller and narrowest part of the insert meet, but wider in the middle. I’m trying to talk him into a stainless 4-blade impeller and a stainless wedge insert (I’m pretty sure you can get those too) but he’s saving his money for a bigger powerhead. His is a 50 Mariner, and it’s OK once he’s on plane, but takes a long distance to get on plane when the boat is loaded for sandbar fishing. I think there’s a tradeoff between motor weight and power – when you have a very heavy motor, you ride lower when idling, so you can’t use the boat for exploring untested stretches of water as well – when you’re up, you’re fine, but when you have to stop suddenly, you need more water. I think the four blade prop will give him the jump out of the hole he’s looking for. I guess the next bump up in powerhead size is only a 15 pound difference though, since his Mariner is about ten years old. I’d be interested in finding out about these pods you put on the transom.
We learned about ten years ago about sucking sand through to the point of impaction – we got her plugged several times in that first year to the point where you couldn’t turn the engine over. We had to get out and drop the guard off and rinse the sand out of the lower unit (and drag the danged heavy rig into deeper water) before we could go on – not fun. Haven’t had that problem since – a few twenty minute downtime sessions on the way out fishing are enough to teach anyone, I guess. It’s inevitable that you’ll suck sand through, though, and with aluminum parts there will be wear – but like I said reshimming is very easy.
The #1 drawback for me (should I ever be in position to spend big bucks on a boat) with jets is that weeds are the ultimate nemesis. I’ve imagined several times the type of arrangement that would take care of it – some of my solutions from fantasyland:
– a scissor-action guard on the bottom that could mechanically chop the weeds when it gets plugged
– a true reverse that you could use to flush the weeds out backwards (you’d have to have a different exhaust system, though)
– a flushing pump that has outlets on the interior of the lower unit so you could flip a switch and blast the weeds out
Not sure at all if any of them are practical, but somehow getting over the weed bug would make the jet the ideal boat.
My dad had an inboard jet at one point – big ol’ fiberglass boat with a V8 engine – louder than heck. Even with all that power, the slightest weediness took her down every time. That boat had the intake on the hull, so you’d literally have to get out into the water (all the way into the water!) and manually remove the weeds. That’s probably where the fantasizing about built-in solutions started.
Love jets, still. Helluva good river boat. The only other real shallow water options are the GoDevil and the airboat. Airboats have all sorts of drawbacks – loud, and the engine takes up lots of boat space. GoDevils are better, but slow and they’re a bit physically draining to drive for a long time. It takes awhile to get good at maneuvering them in tight spots, too, with the lack of reverse.
There’s a new motor out that looks like a combination outboard/GoDevil – I forget what it’s called. It’s still aircooled like a GoDevil, but has a short tiller and is mounted more upright like an outboard. The lower unit is tilted down and is much shorter than a GoDevil’s, but has a long spline and can stump jump to beat hell. There’s no water intake down there for cooling, so it can run right through mud and loose sand. There are some videos of one brand here.
Looks like a good compromise, but expensive.
Happy Hunting,
Matt
Matt, I work at a machine shop so I sharpened my intake grates to a knihe edge and that helps to slice the weeds…but it’s still a problem, just not as bad. Being a strictly river fisherman I don’t encounter many weeds but when I do it can be troublesome. My boat drafts 7.5 inches on drift..that’s pretty good, attribute that to smart placement of heavy items, transom pods, and a lot of bottom area/floatation….I can even idle through some pretty skinny water. I shim mine to .018″ but you can go tighter with stainless…the aluminum flexes more under load. Stainless impellers give one a much better hole shot too. Your buddy may want to buy a new sleeve if the gap is uneven. Snyder jet boats has an excellent how-to/help section for outboard jets…worth checking out. By the way a 1/4 ” inch gap is huge what was he waiting for? .020 might be a little tight for an aluminum impeller??? Good luck and if you guys need any help just ask.
Jason.
He just hadn’t looked at his gap in a long time, obviously. Is your prop a four blade or a three blade? I’ve heard the four gives better power, the three better speed. I’d put the premium on getting on plane, myself, and go with the four. Do Snyder carry the inserts and props? Thanks for the info – we don’t use the boat in weedy areas, but if I was getting one for myself, I’d have to consider that a pretty serious disadvantage, since I fish more in the big river bottoms and less on the tributary – more weeds, less sandy shallows. I still like to be able to get up the tributary around this time of year, though.
I looked at the Snyder jet boat site and those boats look like true flats with tunnels. Do they hydroplane much? They look like they’d be sliding all over the water. My dad’s boat is a true flat with ribs and it even hydroplanes corners, but in a somewhat predictable way. Those ribless hulls look like they’d be hard to control around a twisty river, or do they have some ribbing?
Matt, Snyder boats have about a 8 deg. deadrise at the transom, plus the tunnel so they are not true flats and turn well from the guys I talked to. I think my next boat will be a snyder custom, they put all the flotation under the floor, which is really attractive because I could gain all the interior space lost to the bow and transom foam. plus it would be great to design a cat boat from the floor up…now all I need to do is win the lottery. The stainless impeller gets it’s acceleration advantage two ways: the first I already mentioned, they do not flex like aluminum the second, as you have alluded to is that they have four thinner blades for better bite. Wooldridge boats is who I get my parts from, Glen Wooldridge actually developed the stainless impeller, I have talked with him and he is very helpful. For the longest time the founder of outboard jets did not beleive in the internet…they have a site up now, albeit archaic…and you can get parts through them directly too.
Jason.
Matt, oh yeah, if you want to dust off your dad’s old boat…newer inboard jets can be fitted with a “stomp grate” to alleviate having to go swimming to unplug intakes.
Jason.
Thankfully, my dad got rid of that old beast anyway – it was like driving a Harley down the channel – loud as hell. Didn’t much like it anyway – not designed for fishing, so what in the heck good is it? I can’t be out on the water without wanting to fish…
Check uot these jets http://www.smallboats.com (55hp johnson) they say they can run over sand and weeds no problem
Wrong site thisis the one http://www.smalloutboards.com
check out the ProDrives………… i wouldnt mind seling my Merc 20hp and my GoDevil 20hp and buy a ProDrive. But they are over $4 grand. i would talk more but i am on my way out the door fishin…. 
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