rpm big difference twin engines

[Mainah]

Yeah the Riva spacers I got were obviously the wrong ones, but I didn't really like the way they did them anyway. I ordered them before I took anything apart just so I'd have them, but I should have just known I was going to make my own anyway. The way I made them, it's a smooth transition through the throttle body and into the intake, with the bore opening up as it goes to meet the "bump" in the manifold. I would have liked to port out that bump, but it's part of the strength of the manifold where it necks out for the throttle body mount. I did open up the "bump" a bit to match the inside diameter of my insert.

As far as a reflash, I'm still trying to gather info on that. If you guys know about the HPTuners or EFILive tuning software/hardware, go on the HPTuners forum and you'll see my screenname pop up. I've taught a lot of guys how to tune GM engines. So there's no way I'm paying for a handheld "tuner" with preset maps on these Yamaha engines. I haven't gotten around to it yet but I'm going to play around with seeing if I can read and edit these ECM's myself. If all else fails and I want to go big with adding turbos, I might actually just buy Motec ECM's for them! (yikes!) For now I'm just doing cheap, easy mods.

Thanks guys! And yeah, I copied/pasted this as my first post on the YJB forum and it wouldn't even let me post without a mod approving it! Not a good first impression. haha. I own a Cadillac CTS-V Wagon. The main Cadillac forum is HORRIBLE. The CTS-V Owners forum is AMAZING. Probably the same situation with these very similar jet boat forums?


Oh and yeah, I ripped those snorkels out of the intakes right away! As with the huge plastic "mufflers" in the exhaust. Those went bye-bye after my first time out with the boat. Along with the 4 feet of extra engine flush hose and about 6 feet of extra battery cables. WTF??? I'm from the auto industry. I've NEVER seen this kind of shoddy workmanship as I've seen so far on the building of this boat. Thankfully the engines are "pure" Yamaha.

Great to have someone with your skillset and experience onboard. Anxious to see what you come up with.

 

[gmtech16450yz]

Thanks AGAIN guys, I REALLY appreciate it!
I'm happy to be here, it sounds like you have a nice forum here. (the "other" place has only 10 views and no replies on my first post there. lol.)

I'm happy to pass along any tips or info I figure out on this boat. Likewise, I'm somewhat a newb also so I'll be reading as much as I can on here and elsewhere and asking lots of questions to get up to speed on this boat thing. lol. One of my favorite boats when I was growing up was a 17 foot ski boat with a 289 Shelby GT350 engine in front of a Berkeley jet. I loved that jet! So at least I'm not a jet newb!

I'm still trying to get info on reading and flashing these ECM's. I'm literally going to wire in an OBDII diagnostic connector and see what I can read with the automotive hardware and software I have. It's basically just CAN HIGH, CAN LOW and a data line, it's nothing crazy. I'm actually wondering if these ECU's are used on anything automotive. Doubtful but possible. It is all just basic engine management though, it's not like they re-invented anything as far as the engine control goes. So what's the story on the YDS or YDIS2 or Maptuner X? Anyone on here using them? (I know, I should start a new thread for this.)

 

[swatski]

Thanks AGAIN guys, I REALLY appreciate it!
I'm happy to be here, it sounds like you have a nice forum here. (the "other" place has only 10 views and no replies on my first post there. lol.)

I'm happy to pass along any tips or info I figure out on this boat. Likewise, I'm somewhat a newb also so I'll be reading as much as I can on here and elsewhere and asking lots of questions to get up to speed on this boat thing. lol. One of my favorite boats when I was growing up was a 17 foot ski boat with a 289 Shelby GT350 engine in front of a Berkeley jet. I loved that jet! So at least I'm not a jet newb!

I'm still trying to get info on reading and flashing these ECM's. I'm literally going to wire in an OBDII diagnostic connector and see what I can read with the automotive hardware and software I have. It's basically just CAN HIGH, CAN LOW and a data line, it's nothing crazy. I'm actually wondering if these ECU's are used on anything automotive. Doubtful but possible. It is all just basic engine management though, it's not like they re-invented anything as far as the engine control goes. So what's the story on the YDS or YDIS2 or Maptuner X? Anyone on here using them? (I know, I should start a new thread for this.)

I have the Maptuner 1 (original but somewhat upgraded software) - happy to send it to you if you want to play with it. I don't know anyone else with a boat here who used Vtech.
My experience was actually great. With no boost there is not much to gain from revving the engines higher, but I've seen a definite boost in power and their stage 1 programs also gave me super nice and smooth throttle response that was strikingly better than the factory.
I also liked the fact that with the Maptuner you can reset everything back to the factory settings, as it copies and stores the OEM ECU content. It also preserves all the no wake and cruise assist functions, although I only tested it in a pre- Connext boat. Should matter though.

--

 

[Mainah]

The ECU hardware I/O will be slightly different with Connext but the protocols for the rest of can bus should be the same as the just built on top of the ecus they had making them a bit more extensible. Of notable differnence besides the extra wiring for connext to read some of the engine data from the ecus is cruise up and down function if you have those buttons on Joystick that communicates with connext over propriety N2K pgns and then connext sends the signal over the engine canbus. Another thing to consider is there will be a differnce in the programming for the CARB models.

 

[gmtech16450yz]

Wow, what a nice offer! Sure, I'd love to get a chance to play with some of this hardware/software before I decide what to buy.

Yeah, I totally agree on the gains on an NA engine. There's usually not much to gain in automotive engines either. Forced Induction engines are so easy to get power out of! The Sky Redline in my video originally had a 2.0L Direct Injected turbo 4 in it. They're rated at 260/260 at the crank power from the factory. I had that engine up to almost 500whp/500wtq, which is over 600/600 at the crank. Stock boost was 9-12psi, I was running it at 30psi for 3 years before I finally bent the stock rods! Yeah, forced induction is awesome for tuning, gaining 100hp on an LSA or LS9 is simply a matter of changing some numbers in some tables in the ECM. Knowing WHICH tables and WHAT numbers is the tricky part. That's my expertise and experience.

 

[gmtech16450yz]

Now we're talking! lol.
Yeah, my boat is a CARB model so I know it's detuned as far as ignition timing and fueling goes. (Sssssshhhhhhh, don't tell anyone I might modify my CARB legal engines. hahaha. Has anyone ever actually gotten in "trouble" for modifying a California boat?)

If you guys help me out on the first part of the tuning learning curve and hardware/software setup, I'll no doubt have discoveries once I get into the programming of the ECM's that I can share. I'm an "outside the box" kind of guy and although there's a few players in the "tuning" market on the watercraft side, I'm betting their knowledge is pretty limited. Just a hunch, simply because there's not much market or experience in tuning marine stuff.

 

[Mainah]

Now we're talking! lol.
Yeah, my boat is a CARB model so I know it's detuned as far as ignition timing and fueling goes. (Sssssshhhhhhh, don't tell anyone I might modify my CARB legal engines. hahaha. Has anyone ever actually gotten in "trouble" for modifying a California boat?)

If you guys help me out on the first part of the tuning learning curve and hardware/software setup, I'll no doubt have discoveries once I get into the programming of the ECM's that I can share. I'm an "outside the box" kind of guy and although there's a few players in the "tuning" market on the watercraft side, I'm betting their knowledge is pretty limited. Just a hunch, simply because there's not much market or experience in tuning marine stuff.

I have zero tuning experience. I am just a data guy (corporate big data) for a living with an electronics hobby. I can build boards to read and send raw data streams but without knowing the protocol/mapping/IO that data is all but useless. If I can get the protocol/mapping/IO then I can program software to do something with it. From what I have read the Yamaha outboards communication is something that you can get your hands on but I have not found anything published on these 1.8l na engines and there only appears to a be a couple of players who have figured it out in order to sell their services, devices, and registration keys which are not cheap.

I would love to get more acceleration and top speed out of my boat safely and can bet there are more here that want the same. For what it is worth (not much for engine mods) I am willing to lend my knowledge and skills to the effort but I am not willing to use my boat as a test subject for anything that could cause downtime.

 

[Seadeals]

On the RPM topic, I completed test runs through the full RPM range with YDS hooked up. As I was solo, I set the GoPro up to record the action on the gauges. I also tried to shoot the laptop screen in motion but the lighting washed out the screen. I can say to my personal satisfaction that from what I witnessed, my port tachometer is indeed inaccurate and reads approximately 500 RPM high at 5000 RPM and up. I also ran the port engine on the starboard tachometer and observed the lower "normal" RPM indication that I see from the starboard engine. I can't speak for the new boats @Ronald but @Billtex2000 if you have not made any progress, you can definitely test the port engine on the starboard tach easily. My harness (as laced) will not quite reach to test the starboard engine on the port tach; but I had YDS running on that one so I observed it in real time. On long WOT runs (43-44 mph), I did see the YDS RPM show up to around 8150 or so. I used to think I needed to stagger throttles in cruise to match RPMs up between the tachs; but once I was confident one of the two was off and the ECMs would be matched closely at the top end, I stopped bothering because in reality, they were running at the same approximate RPM.
Here is the port on the port tach.

and below is the port engine on the starboard tach with the starboard engine on YDS reading ~8100- Bingo.

Just to be clear, I was NOT doing 42 mph on one engine! LOL

 

[Billtex2000]

Wow, that's enlightening! I do in my heart of hearts feel that one tach or the other is inaccurate. I think I said before that the engines definitely SOUND like they are in sync, and when I match the tachometers by throttling back in starboard engine, they don't SOUND in sync at all. After oil and plug changes in the Spring and the bottom is clean and waxed I'll definitely re-evaluate my top speed and swap the wires to get a feel for how accurate my RPM's are reading. Unfortunately, it will need to wait until spring.
To be continued...

 

[Ziess21]

I have zero tuning experience. I am just a data guy (corporate big data) for a living with an electronics hobby. I can build boards to read and send raw data streams but without knowing the protocol/mapping/IO that data is all but useless. If I can get the protocol/mapping/IO then I can program software to do something with it. From what I have read the Yamaha outboards communication is something that you can get your hands on but I have not found anything published on these 1.8l na engines and there only appears to a be a couple of players who have figured it out in order to sell their services, devices, and registration keys which are not cheap.

I would love to get more acceleration and top speed out of my boat safely and can bet there are more here that want the same. For what it is worth (not much for engine mods) I am willing to lend my knowledge and skills to the effort but I am not willing to use my boat as a test subject for anything that could cause downtime.

Glad to have your expertise here! Welcome to the forum!

 

[Seadeals]

Just an update on RPM differences: @Stegaus sold me his extra tachometer (thanks!) and I finally replaced my port tach with it and hit the water. The new tach matched up with the starboard tach soooo much better. I no longer feel like I needed to split the throttle levers to match rpm. A smaller split finally appears right at wot but is now only 200 rpm indicated. Just to reiterate, the engines themselves at wot are actually matched as proven by YDS even though tachs show a difference.

 

[MidnightRider]

Hmm. My "fix* is to simply put the sense wire where it belongs, literally move it from one battery terminal to the other. The guys putting the boat together simply can't follow directions or the directions are wrong.

Sounds like that thread makes it a lot more work. "System" and "Aux" would end up being "Starter" and "House", but to me that's not exactly right. The "System" voltage should be exactly that, the battery that's powering the Connext display.

Some of you guys can look at which battery the small gauge red wire is hooked to on your boats. Imho it's supposed to be on the starter battery. That way the Connext display reads it's own voltage internally and the starter battery externally. BTW make sure you put the red wire directly on the starter battery post.

Just reading through all this in gearing up to try and figure out this mod. Found something interesting though in regards to this. I think what you are saying makes sense as to what is House and what is Starter but what is interesting is that the Manual indicates the opposite. The manual states that the System is Starter and that the Aux is House. So all of this indicates to me that Manuals, Wiring, and (probably) Setup Instructions are out of sync and likely the reason for this not working from factory/setup.

 

[Billtex2000]

Ok, so...
Had nice flat water today, no wind to speak of, full tank of gas, clean bottom, fresh oil and plugs. Wife and I were on the boat and I opened her up (the boat, not the wife lol). Saw 42-43mph on the speedo at WOT. Tachs were at 7900/8400 respectively. Motors sounded GREAT! I was very happy.
I have a spare tach that I'm going to swap out with the Port to see what happens.

 

[Seadeals]

I see exactly the same speed. Based on all my live YDS readings at WOT, I promise the computers were keeping them both right at max between 8000-8100 and the tachs are just doing a bad job of translating digital accuracy into analog needle movement.

 

[Funtacular]

Sounds like you simply need to adjust the throttle cables. @JetBoatPilot did a great video on this....see the video below!

I keep searching for these throttle cables but cannot find. Are these only on newer boats?

 

[svana]

Sounds like you simply need to adjust the throttle cables. @JetBoatPilot did a great video on this....see the video below!

I keep searching for these throttle cables but cannot find. Are these only on newer boats?

Not to keep bringing up a dormant post, but rather to keep all the info in the same place - am I correct in thinking this won’t work with the MR-1 engines? Was gonna go work on the boat today and don’t think I have those units on my 08 SX230.

 

[zipper]

Not to keep bringing up a dormant post, but rather to keep all the info in the same place - am I correct in thinking this won’t work with the MR-1 engines? Was gonna go work on the boat today and don’t think I have those units on my 08 SX230.

Correct, we do not have those on the MR-1's. The throttle cables run from the binnacle to the throttle body, with no TPS in between.

I believe they started using a TPS with the 1.8l (2010+) motors.

 

[svana]

Correct, we do not have those on the MR-1's. The throttle cables run from the binnacle to the throttle body, with no TPS in between.

I believe they started using a TPS with the 1.8l (2010+) motors.

So I assume there’s no (easy) way to tweak ours in a similar fashion to match RPM’s?

 

[zipper]

Correct again. You can try adjusting the throttle bodies, you will get it a little better on one end but lose it on the other end. The adjustment is not linear from 0 to WOT. I gave up and just run with port throttle slightly ahead of starboard to sync.

 

[svana]

Correct again. You can try adjusting the throttle bodies, you will get it a little better on one end but lose it on the other end. The adjustment is not linear from 0 to WOT. I gave up and just run with port throttle slightly ahead of starboard to sync.

Gotcha. Man...that'd irritate the heck out of me lol. More so than my couple hundred RPM difference anyways...