New to me Ar190 2020

[Shackdizzle]

I just bought a ar190 yahama with 18hrs 2020 I am really excited about this boat. I took it out for the first time and I couldn’t get it to go over 23mph I had 5 adults in the boat and when pulling two of them on a tube I couldn’t get over 14-17. Mph. I had the dealership install a l13 cone I’m at 4000+ feet is there something wrong or something I can do to get a little more speed?

 

[Thermobrett]

Seems slower than it should be, remember it’s not super charged so you won’t have the added speed 180hp compared to 250hp with the super charger. Research on this forum about the wear ring and the gap. Clean out plug is/was secured properly? What did your RPMs max rev at? Maybe the throttle linkage needs adjusted? Is the hull clean if build up, dirty hull will create drag as crazy as it sounds. Check your air filter and oil level too. If the oil level is too high, you may get blow by saturating the air filter not letting it breathe properly. Adding in @2kwik4u as your an AR190 guy and may have some pointers or ideas??

 

[Babin Farms]

From what I’ve read of the 190’s that’s about al your going to get with 5 adults in the boat.

 

[2kwik4u]

Thanks for the tag @Thermobrett

@Shackdizzle

I think you need to repitch the impeller for that altitude. Even a sealed tunnel and L13 cone won't get you where you need to go at 4k elevation. At 500'-ish I can drag a tube with 2-3 people well into the mid 20's if I want to (don't do that, it's sketchy and borderline unsafe). Only mods I have are a sealed intake tunnel, L13 cone, and removed spark arrestor. I can run around 40-42mph WOT at 7,550 rpm.

First, some questions.

What WOT rpm are you turning? Should be up near 7,600rpm.

What spacers are installed with the L13. I've found best performance is with all except the gold installed. That cone is easily tunable, and you can get some performance back from that.

Next, how are you loaded while tubing. Lots of of people in the bow will KILL the thrust on the 190's. When doing watersports, put your heaviest people in the back corners, then lighter as you move forward. If you can, put coolers under the rear seats. Best tubing I've ever done, I had two "larger" folks in the back corners. Makes a noticeable difference in boat attitude and thrust effectiveness.

 

[SummitBound]

Would definitely get it checked out - that seems low even with elevation. I regularly get 33-35 with 4 adults and gear. I am at 500 elevation but wouldn’t expect that much drop off

 

[Shackdizzle]

Thanks for the tag @Thermobrett

@Shackdizzle

I think you need to repitch the impeller for that altitude. Even a sealed tunnel and L13 cone won't get you where you need to go at 4k elevation. At 500'-ish I can drag a tube with 2-3 people well into the mid 20's if I want to (don't do that, it's sketchy and borderline unsafe). Only mods I have are a sealed intake tunnel, L13 cone, and removed spark arrestor. I can run around 40-42mph WOT at 7,550 rpm.

First, some questions.

What WOT rpm are you turning? Should be up near 7,600rpm.

What spacers are installed with the L13. I've found best performance is with all except the gold installed. That cone is easily tunable, and you can get some performance back from that.

Next, how are you loaded while tubing. Lots of of people in the bow will KILL the thrust on the 190's. When doing watersports, put your heaviest people in the back corners, then lighter as you move forward. If you can, put coolers under the rear seats. Best tubing I've ever done, I had two "larger" folks in the back corners. Makes a noticeable difference in boat attitude and thrust effectiveness.

 

[Shackdizzle]

I went out by myself today and I was Cruising at 29 miles an hour 6878 RPMs it was a 48degrees no wind and glass water. I’m fine I don’t need to really go much faster I just want to make sure I’m getting the best performance out of the boat. If I do decide to get a different pitched impeller what would you recommend?

 

[2kwik4u]

I went out by myself today and I was Cruising at 29 miles an hour 6878 RPMs it was a 48degrees no wind and glass water. I’m fine I don’t need to really go much faster I just want to make sure I’m getting the best performance out of the boat. If I do decide to get a different pitched impeller what would you recommend?

You're down on revs. Should be closer to 7,600rpm. Those last 600-700 revs will amount to some considerable speed. For reference, with just myself and the dog at 500ft, I can cruise at 30mph around 6,200 rpm or so. 41-42mph comes from being right up around 7,550 rpm with a light load and the bimini stowed. With both boys in the bow, the wife, the coolers, the dog and the bimini deployed, we usually top out at 38-40mph. Slight chop is your friend, glass water is always a mph or two slower. You likely can't get to full revs because of the thinner air up at 4k ft elevation. It's about 5% thinner than it is at 500ft. Less mass going into the motor results in a reduction in power. You need to reduce the load slightly by reducing the pitch on the impeller, to get some more revs. Because fluid dynamics isn't linear in terms of pump flow, it works out that the revs are more important than the pitch in terms of generating pressure. SO, pitch down a bit, get the revs up and you're likely to see some better speeds.

Now, to get you the revs you need, you need to go to a "shorter" pitched impeller. What exactly that pitch number is, I'm not sure. I'm a bit out of my depth on the numbers and what changes what for which elevation. You see, I'm going into my 8th season, and I've never had the pump apart on my boat. I'm still running the stock impeller. I've heard it's an easy switch, but I've not personally done it. I do know that I've read nothing but good or great reviews from people that have worked with Impros. I forget the guys name there, but several forum members have had them either repitch the stock impeller, or they've purchased a new one from him, and swapped it out. I would call and talk to them. Tell them the situation, and see if they have some advice on which impeller is best for you.

In the mean time, while you're waiting for a new impeller to come in (We love spending other peoples money around here ) I would suggest taking ALL of the spacers out of the L13 cone, and seeing what that does for you. Good chance it won't "hook up" quite as well on the initial take off, however you might get some revs back on the top end. I've found that you can overload or "stuff the pump" a bit if you have all of the spacers in. This reduced my revs by ~100-200 on the top end. I pulled one spacer out and got those back. pulled a second spacer and started hitting the limiter, so I put them back in. It was a subtle change, and won't get you to 35, but might help a little along the way.

I can't stress this enough. ANY weight in the bow will kill performance on this boat. Couple years ago I did an experiment during a group outing. In the morning, it was cool and everyone sat in the back. Had 4 adults, and the worlds largest Yeti cooler on the upper deck of the swim platform. We ran a solid 42mph out to the cove. On the way home that evening. Same 4 adults, but ladies in the bow, and the cooler about 1/2 empty (drained the melted ice out, and most of the beer was gone), and we only got ~38mph. Ladies got cool, so they moved to the back. Almost instantly picked up to 42mph again. They weren't large ladies, but moving ~300lbs from the bow made a significant change in performance.

I can't remember when they changed the hull on the 190's. Mines a '17 and I KNOW it has the previous generation hull. I *think* you have the new hull on the '20 model. There was a marked decrease in top speed when they changed. I'm unsure if it was hull shape, or if the boat just got heavier in general, but I remember there being some discussion about it. SO, you might not ever see 42mph, but you should still see mid 30's or so I would think.

Finally, check out this thread I made a few years ago. This was probably the single best mod I made to the boat to reduce cavitation. This sealant keeps the interface between the intake tunnel (fiberglass), and the ride plate (aluminum) from leaking air into the pump. That area is under a slight negative pressure, and the air leakage in from the interface will contribute to cavitation. Reducing that leakage was a significant increase in holeshot and top end "grip" on the water.

Between the L13, the sealed intake tunnel, and the ribbon delete (spark arrestor removal), my boat isn't really a ton faster, but it's MUCH more consistent. Loading and balancing is less of an issue than before, and it tends to perform just as well in the summer as compared to the cool spring/fall. Fore/Aft loading is still a consideration, however that's more of a trim issue than it is a traction issue.

 

[Shackdizzle]

You're down on revs. Should be closer to 7,600rpm. Those last 600-700 revs will amount to some considerable speed. For reference, with just myself and the dog at 500ft, I can cruise at 30mph around 6,200 rpm or so. 41-42mph comes from being right up around 7,550 rpm with a light load and the bimini stowed. With both boys in the bow, the wife, the coolers, the dog and the bimini deployed, we usually top out at 38-40mph. Slight chop is your friend, glass water is always a mph or two slower. You likely can't get to full revs because of the thinner air up at 4k ft elevation. It's about 5% thinner than it is at 500ft. Less mass going into the motor results in a reduction in power. You need to reduce the load slightly by reducing the pitch on the impeller, to get some more revs. Because fluid dynamics isn't linear in terms of pump flow, it works out that the revs are more important than the pitch in terms of generating pressure. SO, pitch down a bit, get the revs up and you're likely to see some better speeds.

Now, to get you the revs you need, you need to go to a "shorter" pitched impeller. What exactly that pitch number is, I'm not sure. I'm a bit out of my depth on the numbers and what changes what for which elevation. You see, I'm going into my 8th season, and I've never had the pump apart on my boat. I'm still running the stock impeller. I've heard it's an easy switch, but I've not personally done it. I do know that I've read nothing but good or great reviews from people that have worked with Impros. I forget the guys name there, but several forum members have had them either repitch the stock impeller, or they've purchased a new one from him, and swapped it out. I would call and talk to them. Tell them the situation, and see if they have some advice on which impeller is best for you.

In the mean time, while you're waiting for a new impeller to come in (We love spending other peoples money around here ) I would suggest taking ALL of the spacers out of the L13 cone, and seeing what that does for you. Good chance it won't "hook up" quite as well on the initial take off, however you might get some revs back on the top end. I've found that you can overload or "stuff the pump" a bit if you have all of the spacers in. This reduced my revs by ~100-200 on the top end. I pulled one spacer out and got those back. pulled a second spacer and started hitting the limiter, so I put them back in. It was a subtle change, and won't get you to 35, but might help a little along the way.

I can't stress this enough. ANY weight in the bow will kill performance on this boat. Couple years ago I did an experiment during a group outing. In the morning, it was cool and everyone sat in the back. Had 4 adults, and the worlds largest Yeti cooler on the upper deck of the swim platform. We ran a solid 42mph out to the cove. On the way home that evening. Same 4 adults, but ladies in the bow, and the cooler about 1/2 empty (drained the melted ice out, and most of the beer was gone), and we only got ~38mph. Ladies got cool, so they moved to the back. Almost instantly picked up to 42mph again. They weren't large ladies, but moving ~300lbs from the bow made a significant change in performance.

I can't remember when they changed the hull on the 190's. Mines a '17 and I KNOW it has the previous generation hull. I *think* you have the new hull on the '20 model. There was a marked decrease in top speed when they changed. I'm unsure if it was hull shape, or if the boat just got heavier in general, but I remember there being some discussion about it. SO, you might not ever see 42mph, but you should still see mid 30's or so I would think.

Finally, check out this thread I made a few years ago. This was probably the single best mod I made to the boat to reduce cavitation. This sealant keeps the interface between the intake tunnel (fiberglass), and the ride plate (aluminum) from leaking air into the pump. That area is under a slight negative pressure, and the air leakage in from the interface will contribute to cavitation. Reducing that leakage was a significant increase in holeshot and top end "grip" on the water.

Between the L13, the sealed intake tunnel, and the ribbon delete (spark arrestor removal), my boat isn't really a ton faster, but it's MUCH more consistent. Loading and balancing is less of an issue than before, and it tends to perform just as well in the summer as compared to the cool spring/fall. Fore/Aft loading is still a consideration, however that's more of a trim issue than it is a traction issue.

 

[Shackdizzle]

Thanks that’s a lot of great information I appreciate the time.

 

[2kwik4u]

Thanks that’s a lot of great information I appreciate the time.

If there's one thing you'll learn about this particular forum.....it's that we like to talk about our boats

Keep us posted on what you get for a resolution!

 

[anmut]

I would suggest taking it out by yourself and looking at max RPMs and speed. "Adults" (plus gear and coolers) is super relative for weight. Same with pulling a tube - a slightly underinflated tube can cause a ton of drag. Your setup of passengers in the boat can also have a huge impact on performance.

Set a baseline by yourself, go from there.

 

[YoDaddy292]

I think no matter what you are going to find the single naturally aspirated 1.8 motor a tough go at 4,000' with passengers and tubers. The best mod I've heard of for running high elevation regularly is to get a repitch on the impeller. Probably lose some on top but the grunt off the bottom and rpm's are helped greatly.
We are in a twin engine boat and at 4000' we lose about 5 mph and 3-400 rpm. If it was our regular lake up there I'd definitely go for a re-pitch or buy a supercharged boat (I know, I know.........a 195 adds to the budget cost, so easy for me to say .