SX192 RPM Opinion

[REM835]

So after reading thru several great threads, I imagine I am suffering the known heat soak issue on my 16 SX192 issue but have a few questions.

Went out last night and on the first run it maxed at 7300 rpm and 46mph on gps. Every time after it rarely went above 6800 rpm and never over 7050 rpm at 40mph. This was with half tank of gas and two adults. No extra gear. Air temp 90deg, water temp 88deg and around 800 feet above sea level. The pisser was hot but not scalding. It only has 7 hours on it and I am still babying it so not holding it at specific rpm for long periods of time.

Questions:

I was looking around the engine compartment getting to know her and found with full forward throttle, it is not hitting the throttle stop. There is a bit more than 1/4 inch travel left between the throttle pulley and throttle stop. Is it supposed to be like this? I'm thinking this might just be some initial cable stretch from break in and needs adjusted.

I have also read some claim the enigne computer limits you for a certain number of hours during break in. I have not seen a definitive reply and am curious.

Since heat soak is such a known issue, is there any reason to take it the dealer. I don't want to waste my time with the typical it's running normal. I would like to just put the SVHO cooler on it but will wait till warranty is up if I have not upgraded to a 24ft by then.

In the big scheme of things, this isn't a huge issue. Just frustrating cause I want to have the max out of it even if I don't always run it to the max. I still love the 192 for what it is.

 

[SCSX190]

I have an SX190 and can't offer any heat soak advice, atmospheric pressure data or computer limited RPM evidence. In order to max out the RPM on mine it is important to punch it off the line and get her up to full speed instead of trying to work it up to max RPM. If I am cruising @30 and hit the throttle it won't go above 7400 RPM and maybe 36 mph. Also, I now have 17 hours on mine so I waited until after my 10 hour break-in period.

Today I hit 40 with 3 people @7600RPM, maybe higher. This is very close to max speed/rpm on the 190.

 

[USAF_JAY]

I am having the same issues with my AR192 that has 12 hours on it. I also saw the slack within the throttle and adjusted it to reach the stop. by doing this got about 800 rpm. Getting about 7600 out of it now. I might try running it without the air filter to see if there is any restriction and also when at full throttle tug on the throttle cable a bit to see if there is anymore rpms left to get out of the throttle assembly. Sucks that I have to do this on a brand new boat. Running at about 600 ft above sea level here so there should be no reason I'm not getting the 7800 - 8000 that I have been seeing others get here on the forum.

 

[haknslash]

What I don't understand is why the N/A 1.8L engines in the larger boats seem to run in the 7800-8000 range but the 19' boats run a lower max RPM regardless if it's a n/a 190 or S/C 192. Makes me thing the ECU is different, pitched different or something. Today when I was checking hours on the boat I'm now at 11.2 hours and will do my 10 hour service next Friday. Strange thing was it said on the dream-o-meter that my max speed was 51 MPH. I don't know when or where I ever hit that speed because most times I get anywhere from 42-45 MPH with two adults and gear. I've never ran my boat with the Bimini not deployed so I'm hitting the lake Sunday by myself and will test with it still stowed.

Who gets 7800-8000 consistently in a 192? I would love to know what all is done.

 

[swatski]

What I don't understand is why the N/A 1.8L engines in the larger boats seem to run in the 7800-8000 range but the 19' boats run a lower max RPM regardless if it's a n/a 190 or S/C 192. Makes me thing the ECU is different, pitched different or something. Today when I was checking hours on the boat I'm now at 11.2 hours and will do my 10 hour service next Friday. Strange thing was it said on the dream-o-meter that my max speed was 51 MPH. I don't know when or where I ever hit that speed because most times I get anywhere from 42-45 MPH with two adults and gear. I've never ran my boat with the Bimini not deployed so I'm hitting the lake Sunday by myself and will test with it still stowed.

Who gets 7800-8000 consistently in a 192? I would love to know what all is done.

No one does. Unless you reflash the ECU and raise the rev limiter. 7800 is possible actually, but most 1.8l N/A boats are in the 7400-7600 range max.
7800-7900 RPM is the max at which point the electronic rev limiter kicks in, stock 1.8 pumps will hit max about 7700 sustained at WOT.
Here is the rev limiter table for 1.8l n/a, but it really only kicks in when you cavitate out of the hole or something.

--

 

[REM835]

Thanks @swatski and @USAF_JAY. Hopefully once I adjust the throttle cable it will get me closer. The heat soak itself is agrivating. Wish Yamaha would address it but I'm just preaching to the choir on that front.

Side note...Is it possible or anyone know if you can reset functions on the gauge LCD, ie max speed, distance traveled?

 

[swatski]

Thanks @swatski and @USAF_JAY.

Side note...Is it possible or anyone know if you can reset functions on the gauge LCD, ie max speed, distance traveled?

I think you just press and hold one of the buttons. I used that to reset "gallons used" of fuel, found it more accurate and reliable than fuel gauge (by far).

 

[REM835]

I think you just press and hold one of the buttons. I used that to reset "gallons used" of fuel, found it more accurate and reliable than fuel gauge (by far).

Yup...I just tried it. You select what you want to reset then press and hold the "T" button.

 

[Dieselmore]

My AR192 now has 23hrs on it and from the speedo I've never seen it above 42-43 mph, more often it reads 38-40mph (haven't tried the gps yet)
My rpm is usually 6800 RPM sometimes I'll see it get to 7k for a few seconds. Ambient temp is around 110 deg and water temp around 90 deg usually with two adults and two kids.

My throttle cable didn't reach the end as well, I adjusted it out. For me adjusting the cable didn't seem to make much of a difference.

Before I bought the boat I watched a video of boattest.com doing 50mph in the boat. So that's what I was expecting. The top speed is a little disappointing, I'm very pleased with the rest of the boat.

 

[BakedZiti]

My AR192 now has 23hrs on it and from the speedo I've never seen it above 42-43 mph, more often it reads 38-40mph (haven't tried the gps yet)
My rpm is usually 6800 RPM sometimes I'll see it get to 7k for a few seconds. Ambient temp is around 110 deg and water temp around 90 deg usually with two adults and two kids.

My throttle cable didn't reach the end as well, I adjusted it out. For me adjusting the cable didn't seem to make much of a difference.

Before I bought the boat I watched a video of boattest.com doing 50mph in the boat. So that's what I was expecting. The top speed is a little disappointing, I'm very pleased with the rest of the boat.

You should be seeing 50mph on speedo, I've hit that with two people in the boat. Water temp and air temp does affect this but I'm in middle georgia with warm water and consistent 95+ degree air temps

 

[Dieselmore]

Yeah I haven't seen 50mph on my speedo yet. I've been debating doing some of the common mods, I just don't want to make it unreliable...

 

[Summers420us]

Yeah I haven't seen 50mph on my speedo yet.

Maybe your speedo does not lie as much as others?

 

[Dieselmore]

Very true I'll try to GPS it this weekend and compare it to the speedo

 

[Dieselmore]

So last night I downloaded a speedometer app and headed to the lake. First run Bimini top up, full tank of fuel, wife and 2 kids she ran 38 mph on the GPS and speedo read exactly 38mph. It was dead on. Later leaving Bimini down GPS read 39 and speedo read 39. Looks like my speedo is dead accurate but my boat needs another 11-12mph, for me to be happy. Haha

 

[REM835]

On GPS I got 43 mph on the first run. I adjusted the throttle cable last night since I found it was off a bit. If it ever stops raining I will be able to get it out and see if that helps any.

 

[Dieselmore]

On GPS I got 43 mph on the first run. I adjusted the throttle cable last night since I found it was off a bit. If it ever stops raining I will be able to get it out and see if that helps any.

I adjusted my throttle cable about a month ago or so. For me I didn't notice any change at all. I'm curious to see if you do.

 

[Tom V]

You guys are having the same issue we all have run into. Heat soaking is the problem and the only resolution is a larger intercooler as you probably have read on our other posts. Running with or without the air filter makes little to no difference, possibly helps on excelleration a little bit but hard to say, the boat will run properly and have enough torque to keep you and the entire family with coolers and other crap loaded on board at minimum of 47 mph all day long. You will hit and maintain roughly 50 mph with 2 adults and a cooler (boat loaded lightly) no problem all day.

Before I completed the mods on my 192 I went to the Keys with my wife and 8 yr old son to do some diving, a full cooler, 2 steal 95 cubic ft dive tanks and our gear, full tank of fuel and a few other misc item and the best the 192 would run was 37 mph wide open, this is what made my mind up on changing out the intercooler and a few other items. The boat now runs at least 47 mph with more gear in it. My Son and my self with a full tank of fuel and loaded cooler can hit 50, sometimes 51 mph and maintain this speed in the 96 degree temps and water temp of 90 any time now. Hope this helps, there is hope for your boats 7600 + should be your max expected rpms.

 

[swatski]

@Dieselmore I believe it is what @Tom V said AND the altitude!

 

[REM835]

I have no doubt that most, if not all of the problem is heat soak. Has anyone had any luck at the dealership as a service issue? I kinda doubt it. I guess if anything a intercooler upgrade will be a fun upgrade to have something to do in the off season.

 

[Tom V]

Yes altitude can can have affects on the rpms, but you guys are running the same numbers speed wise and rpm wise we did and we are at sea level, so I can't say how much the altitude is affecting you guys. If it was just altitude then a simple impeller re-pitch would fix you up. That I know will not get you back 10 mph, but it might get you 1 or 2 mph better. Intercooler is the ticket! Anyone who has done the intercooler swap will tell you its the best thing you can do and you will then Love driving your boat, it really transforms the performance and will make you happy.