Poor performance

[Frey33]

New jet boat owner, 2020 sx190. Have about 30 hrs on the boat. Top speed about 38 mph 1 person half tank fuel, 7400 rpm, verified with gps. Boat is slipped Currently with heavy algae growth on hull due to hot sunny summer and warm waters in Lake Erie, Niagara River.

current top speed at 7400 RPM is about 25 mph.
not sure if algae growth could cause this much of a drop in top speed. I did pull a stick out of impeller that got lodged and feel groove in wear ring. So this could be the problem or possibly combination of the two.

Looking for advice on cleaning hull and thoughts on algae or groove being culprit for reduced top end speed.

 

[sunbyrned]

It sounds to me that there could still be some debris left in there from the stick. If you could put it on a trailer and pull the pump, I would recommend doing that. Not sure about the algae question though.

 

[tim h]

Algae growth will definately slow you down a bit !

 

[anmut]

Pull out of water, pull pump, clean hull.

 

[HangOutdoors]

Did you do the 10hr Service? If so what was the speed and RPM's after that?

 

[Frey33]

Did you do the 10hr Service? If so what was the speed and RPM's after that?

Yes the 38 mph and 7400 was at about 12-13 hrs. Not much algae build up at that point and hadn’t had stick in the impeller at that point either.

 

[sunbyrned]

If you decide to pull the pump, it’s an easy process. Here’s a video. This has fixed my issues that your experiencing a couple of times.

 

[Canuckjetboater]

New jet boat owner, 2020 sx190. Have about 30 hrs on the boat. Top speed about 38 mph 1 person half tank fuel, 7400 rpm, verified with gps. Boat is slipped Currently with heavy algae growth on hull due to hot sunny summer and warm waters in Lake Erie, Niagara River.

current top speed at 7400 RPM is about 25 mph.
not sure if algae growth could cause this much of a drop in top speed. I did pull a stick out of impeller that got lodged and feel groove in wear ring. So this could be the problem or possibly combination of the two.

Looking for advice on cleaning hull and thoughts on algae or groove being culprit for reduced top end speed.

@Frey33 .....yes - algae growth can substantially reduce your mph..... the more growth the greater the loss of mph. As well, I like @sunbyrned suggestion. From what you describe you will need to pull the boat to clean the hull. There are commercial applications to apply, let sit and rinse with a nozzle from a garden HOSE. I say garden HOSE because IMO manufacturers of pressure washers should receive kick-backs from glass and gel coat shops for the damage many boaters do to their hulls from pressure washing. Pressure washers machines are IMO guaranteed to wreck brickwork, destroy decks and cause osmosis blistering to boats. To keep speed robbing algae off my pump/hull about every 10 days I anchor our 2020 SX 195 in a sandy cove in about 4 feet of water and using a medium stiff car wash brush scrub the pump and hull. It takes about 20 minutes and the hull is gleaming afterwards.

 

[sandtiago83]

I have a 2023 sx190 . My dealer has been in the business along time with theses boats, he specifically told me not to break it in how the manufacturer tells you to break it in. So I followed his break in procedure and I have gotten my top speed at 41 mph in the Hudson River with a lot of chop, 3/4 tank and 4 adults and gear. I feel like I could have gotten to 42-43 as I was only at about 7000 rpm. He said if you break it in the way he told me to you will get the top speed you can out of it. So I gotta say the break in procedure is very important to how the vessel performs.

 

[HangOutdoors]

I have a 2023 sx190 . My dealer has been in the business along time with theses boats, he specifically told me not to break it in how the manufacturer tells you to break it in. So I followed his break in procedure and I have gotten my top speed at 41 mph in the Hudson River with a lot of chop, 3/4 tank and 4 adults and gear. I feel like I could have gotten to 42-43 as I was only at about 7000 rpm. He said if you break it in the way he told me to you will get the top speed you can out of it. So I gotta say the break in procedure is very important to how the vessel performs.

Sounds like some BS coming from the Dealer. Not sure how altering break in period or process will net anyone higher speed. It is all mathematics based on weight, pump size, humidity, RPM's, thrust, air temperature, water temperature and altitude, drag and wind, fuel mixture, air flow through filter and spark plug condition.

 

[sandtiago83]

I understand how combustion work. I’m not saying that he was correct or I am an expert, but I see the post on how some people are not getting the full speed from there vessels . But it does make some sense if you are breaking in a new motor and you do not break it in correctly with the expansions of the piston sleeves that you could get slower or a bit faster with the boat . That’s just how he explained it to me and I did not have a problem getting mine to top speed according to Yamaha specs of 40-42 mph. With a semi full load in unlikely water conditions.

 

[Thermobrett]

I say if you are getting 40+ mph out of a 190 that is pretty damn good. Best I have gotten out of my 195 was 51 with the top up, two adults and 40 gallons of fuel.

 

[sandtiago83]

Yea before I bought it I seen people were not getting the speed the manufacturer called for, even with single rider half tank on a glassy lake water. So when I bought mine and asked him what’s the top speed on it? He laughed and said believe it or not it all depends on your first few hours on it, so he told me to break it in exactly how I tell you and you’ll get the top speed on it . He said he tells people this and some do it and some don’t and the people who break it in how he talks them, they get a few miles an hour faster than those who don’t . So not saying the break in process has anything to do with it but I did it how he said to do it and at around 10 hours in the Hudson I gave it full throttle and got over 40 miles per hour on it . So I am pleased with how it performs. For a 190 . That was top down 4 adults 3/4 tanks with some chop .

 

[Thermobrett]

I say you’re winning! Like @HangOutdoors said, I don’t think the break in period has much to do with the speed as it does the overall heath of the engine. Sounds like your dealer may be slipping people so bad info but you caught on.

 

[jdkaeser]

For the OP, I would agree to pull the boat out, clean the hull and check the pump.

For everyone with ranging speeds. Top speed in these boats is all about elevation and temperature. If your at sea level, expect the fastest numbers. Decreasing as you go up in elevation. I'm at about 600' just north of Cincinnati and my best number in my 195s is 51MPH and that has only happened once on a 40 degree day with 50 degree water temps. Cold air + cold intercooler = more power. Usually hit 47 or 48 during the summer on dead calm water. If I go to Norris Lake in TN (1020'), I get about 44 - 45 MPH. Watt's Bar Lake, TN (741') I'm about 46 - 47. If you live out West, like Lake Tahoe (6224') good luck cracking 40! If you have a NA engine, I wouldn't be surprised if 30 is your number. Gotta get different pitched impellers at that point. For you boys that live in Florida, let em rip!

 

[sandtiago83]

Good information.

 

[HawaiiBreeze]

As a 2017 SX190 owner at sea level, early 40's is the norm.

 

[Cobra Jet Steering LLC]

I have a 2023 sx190 . My dealer has been in the business along time with theses boats, he specifically told me not to break it in how the manufacturer tells you to break it in. So I followed his break in procedure and I have gotten my top speed at 41 mph in the Hudson River with a lot of chop, 3/4 tank and 4 adults and gear. I feel like I could have gotten to 42-43 as I was only at about 7000 rpm. He said if you break it in the way he told me to you will get the top speed you can out of it. So I gotta say the break in procedure is very important to how the vessel performs.

I do it the old way and take 6 hours to gradually break the new engines in and vary the speeds constantly for the first couple of hours I also NEVER REV THE ENGINES ON THE TRAILER or out of the water and any enclosed area like the intake will usually have a lot of growth in it if you leave the boat in the water , get it on a trailer and pressure wash it all clean..

 

[drewkaree]

I have a 2023 sx190 . My dealer has been in the business along time with theses boats, he specifically told me not to break it in how the manufacturer tells you to break it in. So I followed his break in procedure and I have gotten my top speed at 41 mph in the Hudson River with a lot of chop, 3/4 tank and 4 adults and gear. I feel like I could have gotten to 42-43 as I was only at about 7000 rpm. He said if you break it in the way he told me to you will get the top speed you can out of it. So I gotta say the break in procedure is very important to how the vessel performs.

So you HAVE to say the break in is very important, and that you did yours contrary to manufacturing guidelines, but don't post what this process is?

Smh

 

[FSH 210 Sport]

Sure would be nice if the OP would have closed the loop on this thread to help others out..