Another AR190 top speed thread, fully loaded, only 27 mph?

[2kwik4u]

I have a 2017 AR190. It does slow down with a heavy load as well as with strong winds or anything other than perfect seas. To make it a little more powerful when pulling a tube or with a full boat I did - ribbon delete, remove air box and add larger air intake(K&N), and Lucky 13 cone. Ribbon delete added a few more rpms. Moving to a K&N made it a little more loud but gave a feeling of more mid range pulling power. Lucky 13 changed it to feel like more of a rocket when loaded lightly and more manageable when with a heavy load. Each boat is different with the spacers on the lucky 13 which takes trial runs to see what feels best to you. With all spacers I am at 38mph but top at 7200rpm. With only the smallest spacer I am at 7550rpm, top speed 37mph but it takes off like a rocket with absolutely no cavitation. I was on the quest to get above 40 and haven't had luck unless it is glass with the bimini top down. My next step is to repitch my impeller to give that a try.

If I were to only do one I would start with lucky 13 and then go from there.

Same boat, similar mods, same results.

I can get 40 with the Bimini up, but only in good to excellent conditions with nobody in the bow.

@Daryl123 If you're only getting 15mph with full people, something is wrong, or you're at significant (+3k ft) elevation. Most likely you have cavitation problems and are not getting adequate "traction" with the water.

 

[bttally]

Same boat, similar mods, same results.

I can get 40 with the Bimini up, but only in good to excellent conditions with nobody in the bow.

@Daryl123 If you're only getting 15mph with full people, something is wrong, or you're at significant (+3k ft) elevation. Most likely you have cavitation problems and are not getting adequate "traction" with the water.

Yes. At only 15mph he likely needs a new impeller (and possibly wear ring) and to seal his intake. Something is wrong. Oil levels also play a big part in this as well. Make sure you didn't overfill and that your air filter isn't wet with oil.

I wish I could get 40mph with the top up. I've sealed everything, waxed the boat over and over and tried everything I can think of and I'm stuck around 37-38.

 

[HangOutdoors]

Yes. At only 15mph he likely needs a new impeller (and possibly wear ring) and to seal his intake. Something is wrong. Oil levels also play a big part in this as well. Make sure you didn't overfill and that your air filter isn't wet with oil.

I wish I could get 40mph with the top up. I've sealed everything, waxed the boat over and over and tried everything I can think of and I'm stuck around 37-38.

Waxing will slow it down a bit. On my boat it is a couple MPH.

 

[bttally]

Waxing will slow it down a bit. On my boat it is a couple MPH.

Even a hard coat paste wax? Interesting, I haven't heard that before. Seems like it would reduce drag in the water.

 

[mwalker4]

This boattest article still makes me upset. Yamaha SX190 (2019-) | BoatTEST They claim they are testing a 2019, but when you look at the pictures it is a 2018. So if you are buying a 2019+ 190 and do your research, you think top speed is 43mph, like I thought. Of course you can't test your boat because before you buy because of break in rules and nobody has a test unit available. So you buy your boat, get through break-in and it is 2-4 mph less than you thought in perfect conditions. So then you get everyone new to their 190, including me, on this forum saying whats up with my new boat. Thats before all of the California emissions 190's at 5,000 ft boats chime in.

 

[2kwik4u]

Yes. At only 15mph he likely needs a new impeller (and possibly wear ring) and to seal his intake. Something is wrong. Oil levels also play a big part in this as well. Make sure you didn't overfill and that your air filter isn't wet with oil.

I wish I could get 40mph with the top up. I've sealed everything, waxed the boat over and over and tried everything I can think of and I'm stuck around 37-38.

You need cool dry air (likely a big part of the problem in FL), a slight chop, and keep everyone out of the bow.

Had an adults weekend a few years ago. 3 guys 3 girls on board. Biggest Yeti known to man strapped to the swim platform. Got 41mph with all 6 of us in the cockpit. Ladies moved up front for part of the trip and dropped to 36mph. ANY weight in the bow will slow you down significantly.

 

[DTram]

I’m having the same issue. 2019 ar190. Just me and gf can only run 30mph on speedo on nice day. I had 5 adults and 2 kids and could only run 15mph. What is going on is there something wrong with my boat?

I had a similar issue, when you only hit 15 you were simply overloaded. I made a run with myself + 6 adults, was stuck at 15 mph. It needs 16-17 to get up on plane - with that much load you just couldn't get over that hump to plane, and were stuck there. Taking one adult probably would have been enough to get over the hump, and that 15 would've turned into a top speed of around 25-27. Nothing wrong with your boat, you're just finding out the same way I did that these little lightweight boats with small engines are very sensitive to weight and where in the boat people are sitting. Limit yourself to you + 5 + beverage cooler and you should be good to go. Also what others have said about 2018 and older boats, the hull is different / narrower and a few mph faster.

 

[2kwik4u]

I had a similar issue, when you only hit 15 you were simply overloaded. I made a run with myself + 6 adults, was stuck at 15 mph. It needs 16-17 to get up on plane - with that much load you just couldn't get over that hump to plane, and were stuck there. Taking one adult probably would have been enough to get over the hump, and that 15 would've turned into a top speed of around 25-27. Nothing wrong with your boat, you're just finding out the same way I did that these little lightweight boats with small engines are very sensitive to weight and where in the boat people are sitting. Limit yourself to you + 5 + beverage cooler and you should be good to go. Also what others have said about 2018 and older boats, the hull is different / narrower and a few mph faster.

I disagree.

I've had 8 fullsize humans and 3 coolers on board and still be able to get on plane. At one point is was 7 fullsize humans, and one person doing a deepwater start on a wakeskate. It didn't launch excessively hard, but it still pulled him up, and got on plane.

15mph with a full load on an AR190 is not acceptable performance.

Most likely there was cavitation that limited thrust. Seal the tunnel and check the impeller if not at elevation. If you are at elevation, then a more appropriate impeller needs to be found if this loading is a common occurence.

 

[Daryl123]

I had a similar issue, when you only hit 15 you were simply overloaded. I made a run with myself + 6 adults, was stuck at 15 mph. It needs 16-17 to get up on plane - with that much load you just couldn't get over that hump to plane, and were stuck there. Taking one adult probably would have been enough to get over the hump, and that 15 would've turned into a top speed of around 25-27. Nothing wrong with your boat, you're just finding out the same way I did that these little lightweight boats with small engines are very sensitive to weight and where in the boat people are sitting. Limit yourself to you + 5 + beverage cooler and you should be good to go. Also what others have said about 2018 and older boats, the hull is different / narrower and a few mph faster.

So I finally got a brand new double impeller installed, took the boat out yesterday and hit 32mph at 7300 rpm. Something is still not right. 7300 rpm seems really highly to me only going 32mph, what else am I missing here?

 

[Daryl123]

So I finally got a brand new double impeller installed, took the boat out yesterday and hit 32mph at 7300 rpm. Something is still not right. 7300 rpm seems really highly to me only going 32mph, what else am I missing here? That’s with only 4 adults calm water

 

[2kwik4u]

So I finally got a brand new double impeller installed, took the boat out yesterday and hit 32mph at 7300 rpm. Something is still not right. 7300 rpm seems really highly to me only going 32mph, what else am I missing here?

What is a double impeller? Never heard that term before. If you're only getting 7,300 rpm at WOT then you need to reduce the pitch slightly. You should be closer to the 7,800 rev limiter.

7,300rpm might not be far off at 32mph. I was "racing" my buddy this weekend. Just tickled 38mph (headwind, 2adults, 2 kids, dog, coolers) on the GPS and was running at 7,650rpm. My normal cruise is right at 30mph, and we're usually in the 6,950-7,050 range.

Looking for rev limiter info, I found a few threads talking about overfilled engine oil reducing RPM a bit. Might be worth a check next time you're on the water, however I doubt you're going to find 500rpm difference from oil level.

Have you done a ribbon delete? If not, I suggest it if you are comfortable with the risks.
Have you run the blower while doing top speed runs? Helps keep the engine bay cooler, and helps prevent vapor lock. Again, doubt you find 500rpm there, but it's worth a try.

I don't see what elevation you're at. I'm at ~500ft asl. You'll start losing some revs once you get above ~1,500ft asl. Fix for that is, again, a repitch on that new impeller.

 

[Daryl123]

What is a double impeller? Never heard that term before. If you're only getting 7,300 rpm at WOT then you need to reduce the pitch slightly. You should be closer to the 7,800 rev limiter.

7,300rpm might not be far off at 32mph. I was "racing" my buddy this weekend. Just tickled 38mph (headwind, 2adults, 2 kids, dog, coolers) on the GPS and was running at 7,650rpm. My normal cruise is right at 30mph, and we're usually in the 6,950-7,050 range.

Looking for rev limiter info, I found a few threads talking about overfilled engine oil reducing RPM a bit. Might be worth a check next time you're on the water, however I doubt you're going to find 500rpm difference from oil level.

Have you done a ribbon delete? If not, I suggest it if you are comfortable with the risks.
Have you run the blower while doing top speed runs? Helps keep the engine bay cooler, and helps prevent vapor lock. Again, doubt you find 500rpm there, but it's worth a try.

I don't see what elevation you're at. I'm at ~500ft asl. You'll start losing some revs once you get above ~1,500ft asl. Fix for that is, again, a repitch on that new impeller.

 

[Daryl123]

View attachment 186487

It’s a high performance Solas impeller brand new. I’m at 3,000 ft elevation, used 3M scotch weld gasket maker GM18 red to seal everything back up and waited 3 days to test it out.

 

[lazergeek]

It’s a high performance Solas impeller brand new. I’m at 3,000 ft elevation, used 3M scotch weld gasket maker GM18 red to seal everything back up and waited 3 days to test it out.

Did you get stock pitch or was that pitched for your altitude? You may be able to drop a little pitch to get your rpms higher but you would also lose some thrust so it would probably be a wash.

 

[Daryl123]

Did you get stock pitch or was that pitched for your altitude? You may be able to drop a little pitch to get your rpms higher but you would also lose some thrust so it would probably be a wash.

Yes I had it pitched for my altitude, that impeller works great taking off I can feel the difference in acceleration but makes no difference on my top speed

 

[Daryl123]

Yes I had it pitched for my altitude, that impeller works great taking off I can feel the difference in acceleration but makes no difference on my top speed

 

[Babin Farms]

So I finally got a brand new double impeller installed, took the boat out yesterday and hit 32mph at 7300 rpm. Something is still not right. 7300 rpm seems really highly to me only going 32mph, what else am I missing here?

Do you have any cavitation? How many people in the boat? What were you expecting to get out of the new impeller, more top end? Could you not get any more RPM out of the engine?

 

[2kwik4u]

Yea, at 3,000ft asl you're gonna want to adjust the pitch a little lighter. Revs are everything, and they are non-linear.

Even with all that you're likely not going to see 40 at that elevation. I would guess in the 36-37 range is about as good as you'll get. Even with a repitch.

Is cool to see a "double impeller". I hadn't seen that before. Be interesting to see how that compares to some of the work @swatski did years ago on testing with his SX190.

 

[dvrice]

I have a 2021 SX190. My top speed yesterday with 3 people in boat (400 lbs of the 3 people combined) and probably 100 lbs worth of gear like coolers was 32 mph by the connect speedometer. I should have looked at the rpms but didn't.

This seems slow compared to what others are reporting. I guess I would have expected more like 37-38 mph under those conditions.

I'll check rpms next time and report back.

 

[2kwik4u]

I have a 2021 SX190. My top speed yesterday with 3 people in boat (400 lbs of the 3 people combined) and probably 100 lbs worth of gear like coolers was 32 mph by the connect speedometer. I should have looked at the rpms but didn't.

This seems slow compared to what others are reporting. I guess I would have expected more like 37-38 mph under those conditions.

I'll check rpms next time and report back.

The newest hulls are down a bit on speed. They're a shade heavier, and have slightly more planing surface. I think high 30's is the right target for you. I would expect slightly more than 32 though. Check the revs for certain. You should be up around 7,600 rpm or so. Does it cavitate on launch at all? Ever feel like it's "losing traction" throughout the rev range? When was the last oil change and last spark plug change? How does the air filter look? Clean or dirty? Oil level in spec? Overfilled? Underfilled? What altitude are you running at?

The single engine non-supercharged boats are sensitive to loading in the bow killing speed. The second easiest way to lose speed is to operate at elevation.

I checked my '17 AR190 this weekend and WOT with 2 adults, 2 kids and gear was right at 39mph (GPS speed) with revs at 7,550. That was light chop, bimini deployed, and the boys in the bow (they're getting heavy now!). Mine's lost a step or two along the way. I'm guessing the hull is dirty, and I likely have some wear on the impeller/wear ring now that is giving my some slippage. This is me 7th season with the boat, and I've never pulled the impeller on it. Only mods are a ribbon delete, sealed intake tunnel, and L13 cone. Used to hookup like a scared cat on carpet, starting to get a little cavitation on launch, so I'm suspecting wear is finally appearing. 225hrs on it with 99% of those being debris free fresh water. Couple hours in salt water, and maybe 2-3 clogged pumps over the years. I was at ~675ft ASL on these runs.