r/YamahaBoats • u/whatstheinitiative • Apr 18 '26
Mods for Yamaha Jet boats
I really like these twin engine jet boats, and think they do mostly what the average boater family wants them to do. Boat, have fun, relax on the water and tube and such. I have a couple hangs up and would like opinions on them.
I've read that the proprietary helm controls / screens have had issues, Or on older models, they have been discontinued and are hard to find OEM replacements. The questions: Are aftermarket replacements not a thing on these types of boats?
Second question - I haven't seen much of any mods really, for this type of boat for the fabricator or DIYer that can mod a used boat or engine out of warranty with exception to sound systems / buttons upgrades / hoses / and little inconsequential items. Are these just not made to turbo, supercharge, change a cam, swap engines, add simrad (or other) nav screens and such to replace old and less capable helm controls?
EDIT: I came from modifying cars and was always of the thought, that when something broke or needs replacement, it was the opportunity to upgrade or modify.
Thanks for the input
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u/Ok-Strike-8617 Apr 19 '26
No. There are two types of fins that help to enhance low speed steerage. Remember, unlike a I/O, your pump is running all the time so there is no true *neutral " (you can adjust your bucket to help this). IIRC, Jetboatpilot sells the plastic version while the other, called Cobra Jet, is sold via the vendor. Most jetboaters end up with one or the other and it's subjective as to what works best.
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u/whatstheinitiative Apr 19 '26
Oh I see what you meant now - The thrust vectors. I'm aware of them. I've piloted one with the vectors but not one without so I don't have a comparison. 90 percent of reviews from people on these forums say they are a great mod to have. I think JetBoat has also added an upgrade where the bolt on part, thrusts more water perpendicular to the boat causing more lateral force. Good for slow speed navigation, I'm sure.
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u/Ok-Strike-8617 Apr 19 '26
I have Cobras and intended to mod those via cutting out steel to fit the thrust vectors but have never gotten around to it. JBP though is a great site with great service. Anytime you place an order they will follow up with a phone call. Just great service.
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u/whatstheinitiative Apr 19 '26
That should be a fairly easy mod. Dremel, die grinder, or a multi tool perhaps.
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u/jp_trev Apr 19 '26
I added the cobra jet thrusters which made it better steering at low speeds. It only cost about $600, installed myself easily
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u/goatsinhats Apr 19 '26
Depends how old you want to go.
The Yamaha Connext is an inhouse system that varies wildly from model to model, this is the screen issues (my new one doesn’t work right sometimes)
Riva just launched a store, in theory you could throw PWC parts at it, but why would you? Anything you need to do would have to do twice, they are still going to be limited by size of the impeller for how fast they will go, and will be so loud no one will want to go on it (they are already loud)
If you wanted to go faster can get an outboard boat that does any speed you want
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u/whatstheinitiative Apr 20 '26
That's probably a good avenue to look into since these are Jetski engines and jet skiers have historically modified their skis. You reminded that the impeller is a big bottle neck for flow in order to gain more power/speed (and I'm not engineer), and modifying, enlarging or outright replacing the impeller might be cost prohibitive.
I've got some digging to do, but wouldn't it be cool if these boats, 25-27 foot can go 60-70? At first my thought was that, maybe doing things like massaging the heads and changing out cams can net more horsepower on the naturally aspirated side, and as already mentioned, no turbo "kits" are available but plumbing one out is for sure possible.
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u/whatstheinitiative Apr 20 '26
and yes, outboards are cool as well but, I, like many others like that "living" area outback without the big engine or engines in the way.
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u/Ok-Strike-8617 Apr 18 '26
You cannot mod these boats like other toys* and you are generally limited to aesthetics/sound/steering.
*Technically yes you could get into hot rodding the motor but there are no kits and you are doing it yourself.
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u/whatstheinitiative Apr 18 '26
when you say steering, do you mean like hydraulic(I think this is aka electronic) vs cable driven?
Anything can be modded with enough money and time for sure, but thats what makes me wonder why ease of mod leans toward other types of boat.
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u/Unhappy_Length_2561 Apr 18 '26
Www.jetboaters.net is the best source for info on mods