I want bigger displacement engines ! C'mon Yamaha the 1.8s are dinosaurs at this point !

[2kwik4u]

Simple answer => buy a different boat/jet boat to suit your desire/needs. I did. I drive my boat like a drive my car; like it's meant to be driven. I love going fast but I never stay up there; just to dangerous. I feel, the thrill of getting to that speed is the best part. Both the boat and the car does this very well. But, driving at 55+ on my boat and over 100 in the car for extended periods of time, no thanks! That's just an accident waiting to happen. Plus, I can't afford the gas (boat)...

I too am an acceleration junkie. Love hte hit and the pull, but extended time up there isn't for me.

I would like to cruise in the mid/low 40's from time to time. We can get extended periods of glassy water where 40 doesn't really feel to bad. Our trip from Old Hickory down to Nashville on the Cumberland River was this way. Absolutely glass smooth water, and cruising at 32mph or so felt slow. Would have liked another 10mph or so on that trip.

 

[Dean P]

I too am an acceleration junkie. Love hte hit and the pull, but extended time up there isn't for me.

I would like to cruise in the mid/low 40's from time to time. We can get extended periods of glassy water where 40 doesn't really feel to bad. Our trip from Old Hickory down to Nashville on the Cumberland River was this way. Absolutely glass smooth water, and cruising at 32mph or so felt slow. Would have liked another 10mph or so on that trip.

You bring up a great point. The days where the water is like glass is special and a rarity. I would love to WOT (ask me how I know this) but then I miss out on how nice the water is and before I know it, I'm already at my destination. What?!?! Damn! But it was fun.

 

[1WetBoat]

Or buy a supercharged waverunner for us speed freaks and then the boat for family time.
When I feel like exploring local areas or just hitting 70+ i take out the ski. When I want to chill with the family i take out the boat.

 

[2kwik4u]

You bring up a great point. The days where the water is like glass is special and a rarity. I would love to WOT (ask me how I know this) but then I miss out on how nice the water is and before I know it, I'm already at my destination. What?!?! Damn! But it was fun.

I also would have liked more power in the Gulf this spring. I was cruising near WOT, but had heavy winds/waves/passenger count and was only in the high 20's low 30's around 7k rpm. I think this is more a function of the small 19ft hull and N/A engine. A 212X or AR240 probably would've been no big deal to cruise at lower RPM and higher MPH with the given conditions. Was burning around 12gph or so, but felt like it was working the engine pretty hard to maintain that speed. Passengers weren't complaining about anything but the noise

 

[suke]

We went on to discuss this more, but I get their point. I love to go fast in my boat on occasion, but if you pulled the hours on my boat, I'll bet I have less than 10 hours full throttle (out of 200-300). It EATS gas.

How about some nice high torque high mpg Diesels???? (wouldnt be able to sell them in CA!! but they have no water left anyway LOL)

I definitely don't want anything faster that's for sure. Sure would love to surf without being at 6k+ rpms and watching my gas gauge go down to 0 in just a few hours. I want more torque.

Hmmmm I guess a taller prop would do something similar, no? Kill top speed and give me hole shot, but would that also mean less RPMs to maintain a slower speed? I've owned jet skis for damn near ever and I was always shooting for faster and not necessarily more torque.

 

[Dean P]

You guys are killing me...Haven't been out on the boat in 4-5 weeks with all this damn rain. T-storms in the afternoon are so unpredictable.

@suke Have you considered a Lucky13 cone (or similar like WetWolf)? This will definitely help with hole shots.

 

[suke]

You guys are killing me...Haven't been out on the boat in 4-5 weeks with all this damn rain. T-storms in the afternoon are so unpredictable.

@suke Have you considered a Lucky13 cone (or similar like WetWolf)? This will definitely help with hole shots.

I actually don't have an issue with hole shot. What I'm more curious about is lower RPMs while surfing so I'm not drinking so much gas. If I hammer down on my 212x it jumps out of the hole. No issue with that.

 

[Dean P]

I actually don't have an issue with hole shot. What I'm more curious about is lower RPMs while surfing so I'm not drinking so much gas. If I hammer down on my 212x it jumps out of the hole. No issue with that.

Don't mean to hijack the thread but, I swapped out my cone(s) to get better fuel economy. Had to give up a chest squeezing hole shot but more $$ in my pocket for more gas.

 

[yam240sx]

I have the cones , along with ribbon delete and k/n filters .. the boat fully loaded with family aboard hits about 47 if I WOT .. I could get unloaded with just me driving would easily hit 50 + ... but its the MIDRANGE we all want more of , sure who goes around WOT all time ...you would be using less gas with more torque down low and bigger pumps

 

[yam240sx]

IMO we need 400cc increase in these engines along with tested matching spec bigger pumps and impellers .. cam redesign for more midrange without compromising high end so much ..

 

[yam240sx]

The way I would do it I were yamaha .. would be introduce the all new 21ft boat with a SINGLE engine 2.2L bigger pump and impeller .. see how it goes and then introduce them into the twins 25s and above ... Skis will follow ....

 

[biffdotorg]

The way I would do it I were yamaha .. would be introduce the all new 21ft boat with a SINGLE engine 2.2L bigger pump and impeller .. see how it goes and then introduce them into the twins 25s and above ... Skis will follow ....

Those go against every bit of design and engineering they have put into their products so far. So it's easy to say, it will probably never happen.

1. Yamaha is an engine manufacturer first. And their top of the line outboards are already being used on the most powerful outboard powered boats in the world, so they have no need to compete with their best customers. They do in Asia, so look that up when bored.

2. The low profile of the 1.8ltr engine, is what makes it perfect in their waverunners and sportboats, keeping the low entry from the swimdeck, that larger displacement single engines cannot compete with. Anything larger will nearly ruin that design, which is their trademark, that we all love!

3. Yamaha will only develop new engine designs that can be used in more than one application. They are near max mass in the waverunners, and if anything may need to squeeze more power out of smaller displacement to compete. It would be more likely to see more advanced SC or Turbo motors. This multiple use design applies to Sleds, ATV's, SXS, and Watercraft. It's good business, and they very rarely stray away from it. Ask me about my 165hp Snowmobile with an engine derived from an R1 SportBike. And yes, it sounds just as bad ass at 113mph!! PS: the 998T engine in the sled line makes 208hp, but has the potential to do double that. I have a feeling the sound coming from the 1.8 SC at 250hp is much more desirable, than that screaming monster. So be careful what you wish for, if lower noise comes out of one side of your mouth and more power out the other.

4. Yamaha likes to introduce the latest features in their flagship boats first, to the folks with the expendable income to afford it, then trickle down to smaller boats. The only exception being the 195 series, but it was kept to a single engine. If we were ever to see a hotrod again,

I dare say a 215ss? A 21ft dual SVHO would be the most likely next candidate for an overhaul to sooth the speed junkies. As the tech is there, and already out in the 275/255/195 models. They would not release a new motor to revamp that animal.

 

[adrianp89]

You guys are killing me...Haven't been out on the boat in 4-5 weeks with all this damn rain. T-storms in the afternoon are so unpredictable.

@suke Have you considered a Lucky13 cone (or similar like WetWolf)? This will definitely help with hole shots.

We had a beautiful weekend…. Stop making excuses lol

 

[OrangeTJ]

Why not use a larger displacement engine that produces peak torque at significantly lower rpm, allowing the use of greater pitch on the impellers in perhaps larger volume pumps? Seems like that would essentially eliminate the noise issues (or at least change it to a less annoying tone) that some people complain about with these boats.

 

[mwalker4]

As owner of a 2019 190, I believe tne new larger hull has pushed it beyond the capability of the NA1.8L. Most reported topspeeds are 35 to 38 mph. The old hull seem to be 40 to 42 mph which seems to be reasonable for thus class of boat. I will likely go with a 195 in a couple of years but would rather have a NA 2.OL. i really like the boat otherwise.

 

[Enduro900]

When I discussed with the Yamaha product managers the desire of forum members to get higher speed boats, their reply was effectively - "the market we serve is for family runabouts. Could we make faster boats - sure. But keeping standard parts across multiple models keeps pricing down and maintenance easy. Doesn't mean we won't make faster boats, but that there is less demand for +50mph boats than you would think"

We went on to discuss this more, but I get their point. I love to go fast in my boat on occasion, but if you pulled the hours on my boat, I'll bet I have less than 10 hours full throttle (out of 200-300). It EATS gas.

How about some nice high torque high mpg Diesels???? (wouldnt be able to sell them in CA!! but they have no water left anyway LOL)

I agree except why NOT offer the SVHO engines in the 21ft and 25fters & call it a 210SS or something…I picked up a 2012 Seadoo Challenger 210SE with twin supercharged 215’s while I hit the upcoming fall and spring boat shows for my long-term new boat (i wanted to make sure i had something for next season if the industry stays in this shortage again), and the pull from 20-40 is impressive, and hits 53-54mph.

 

[biffdotorg]

I agree except why NOT offer the SVHO engines in the 21ft and 25fters & call it a 210SS or something…I picked up a 2012 Seadoo Challenger 210SE with twin supercharged 215’s while I hit the upcoming fall and spring boat shows for my long-term new boat (i wanted to make sure i had something for next season if the industry stays in this shortage again), and the pull from 20-40 is impressive, and hits 53-54mph.

Understanding the naming convention will help you with this.

Any of the Yamaha boats ending in a 5 already have the SVHO motors. So your wish has been granted already. 195/255/275 As stated in a previous post, it has yet to trickle down to the 21 foot models. As it just trickled down to the 24 footers in 2021, as the 25' 255 series.

If and when it hits the 21' boats, it would more than likely be a 215 model, as they get the advancements first in the 215x/215s or 215ss if ever produced. That hull is also due for a re-design. So it would not be a surprise to see this all change for 2023.

Back to what Julian said, Yamaha is not looking to compete on the top end performance. They are adding it to the boats that needed it to maintain overall performance. The 190 series needed more power, that the 192 did not deliver on. The larger 275, needed a boost out of the gate. And folks would have not bought in on the 25' hull if the bigger power SVHO were not at least an option.

So many are pleased with the performance of the 240/242 series, it's a tough sell to go with a new 25' boat if it had less performance. Albeit small. So they offered both, and I think that is a smart play on their part.

Just like cars and trucks, you can't offer all the goodies to each model line. You have to save something for an owner to lust after. And until you get to the top of the food chain, you will keep lusting. Yamaha is playing the game proper by releasing the most sought after goodies for the top of the line and then trickling down. It creates brand loyalty.

 

[2kwik4u]

Why not use a larger displacement engine that produces peak torque at significantly lower rpm, allowing the use of greater pitch on the impellers in perhaps larger volume pumps?

The problem here is that axial flow centrifugal pumps don't work this way. You NEED revs to develop pressure differential and flow. The physics behind a jet rely on a mass flow rate of water to move through the nozzle. You are trading momentum in the water for a reaction force to the hull. The way an axial flow centrifugal pump works is by accelerating the water by ways of large movements in short amounts of time. The best way to get that is through a high RPM/low torque prime mover.

The curve for these pumps are an upside down parabola (roughly), and as you go down in revs you lose efficiency because pumping losses go up, and slip ratios (traction with the water) go down. The only way to make a low rpm jet work is to have a massive overdrive gearbox in place to get the pump revs you need with low end torque. This adds cost, complexity, and packaging issues, and comes at very low benefit in terms of engine efficiency. You're still going to need to supply 180hp to get that pressure differential generated in the pump, and the subsequent flow through the nozzle.

If anyone wants to do a deep dive. Here's a link to the engineering manual for Hamilton's HJ series. Have a look at the power curves and boat speed, then think about what kind of engine would be used to deliver those power levels and input speeds. These jets are for higher power applications than our boats would ever require, but the curves scale downward fairly well. HJ Designers Manual Eng 2013

Moral of the story here is that (aside from noise) a low displacement high revving engine combines really well with an axial flow pump and nozzle setup. This also leads to a dead simple driveline which is also a benefit for a marine application. I would be really curious to hear how fuel consumption has changed for someone that has moved from a 360hp (twin 1.8L) jet application to a 360+ hp V-Drive application. My guess is that, in general, the fuel consumption is relatively close.

 

[biffdotorg]

If anyone wants to do a deep dive. Here's a link to the engineering manual for Hamilton's HJ series. Have a look at the power curves and boat speed, then think about what kind of engine would be used to deliver those power levels and input speeds. These jets are for higher power applications than our boats would ever require, but the curves scale downward fairly well. HJ Designers Manual Eng 2013

Alas, the four things never to be seen in a Yamaha Jetboat.
1. Hamilton Jet
2. Big Block Oldsmobile V8
3. Hot foot pedal
4. Panty Dropping Metal flake

 

[2kwik4u]

Alas, the four things never to be seen in a Yamaha Jetboat.
1. Hamilton Jet
2. Big Block Oldsmobile V8
3. Hot foot pedal
4. Panty Dropping Metal flake

Dunno about #4 (bass boats have that same look and a not many ladies on them.


Interesting parallel though. That is a relatively high torque low rpm motor (compared to to our 1.8L's) coupled to a jet drive.

Wondering if the relation between cylinder head size/block size and torque production is another driving force. Keeping the prime mover relatively small and light helps with packaging and power/weight in comparison.