Tach

[William Hamlin]

Hi everyone. I'm new to the site as well as new to owning a jet boat.

I took delivery of my SX190 yesterday and during the inspection and walk around at the dealership they explained that the tach was sending some sort of "comm error". Of course they didn't have one in stock to replace it and Yamaha wouldn't have them one for about a week and a half to two. Yamaha told them to use the tach from a 242 until mine comes in.

He explained to me that my boat currently runs well over 55mph at 7600rpm and it's because the tach.

Any thoughts....

 

[Julian]

A tach simply displays data sent from the engine. It has no ability to change engine performance in any way. (I hope he and you are pulling my leg!)

 

[William Hamlin]

That's my exact thoughts. Hopefully going to take it out later today. I'll let you know if he was giving me some BS.

 

[Bruce]

No current production Yamaha boat can reach 55 MPH. The tachometer is simply a display.

 

[Julian]

No current production Yamaha boat can reach 55 MPH. The tachometer is simply a display.

Caveats:

1. On the water
2. True speed (if you are on a fast moving river driving down stream, a couple of models might eek their way to 55 on GPS...but that isn't a true speed)

 

[Mainah]

Believe it or not the tach is what interprets the NMEA 0183 antenna signal and sends a corresponding but different signal to connext in the newer boats. Why? Because the gps antenna was already wired that way on pre connext boats that had gps speedos. So my guess is that sure a 55mph readout is possible because the signal the tach is sending is just a bit different. Would be curious to see a side by side with a phone gps speed app.

 

[William Hamlin]

Well. We were able to take her out today. Had a great time. Got up to 49 mph a a few times according to gages and phone. It was me 185 lbs wife 140 son 125 son 40.

 

[Bruce]

Is she a 190, 192 or 195?

 

[William Hamlin]

190

 

[Bruce]

@swatski, 49 seems crazy fast for a 190 to me. What is your experience?

 

[William Hamlin]

Yep. Seems fast to me too. Did your read the reason for starting this whole thread? I'm new to jet boats.

Regardless of my experience guage on boat matched readout on my phone exactly. The tach read just shy of 8k.

I'm curious if it is because they put the tach from a 242 in my boat and if so why?

 

[Bruce]

A 190 and the 240/242 series have the same engine. The tachometers are not the same part number but they must be compatible.

 

[swatski]

Yep. Seems fast to me too. Did your read the reason for starting this whole thread? I'm new to jet boats.

Regardless of my experience guage on boat matched readout on my phone exactly. The tach read just shy of 8k.

I'm curious if it is because they put the tach from a 242 in my boat and if so why?

With the old style analog speedometer anything is possible, those were pretty "optimistic" usually. But the RPM readings of 8,000 do not make much sense. In these boats the 1.8l N/A engine is rev limited at around 7,800 RPM and most do not come close to that stock (before ribbon delete etc.). 49mph sounds too good to be true as well. Even if it was a cool day and perfect conditions, IMO.

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[swatski]

Hi everyone. I'm new to the site as well as new to owning a jet boat.

I took delivery of my SX190 yesterday and during the inspection and walk around at the dealership they explained that the tach was sending some sort of "comm error". Of course they didn't have one in stock to replace it and Yamaha wouldn't have them one for about a week and a half to two. Yamaha told them to use the tach from a 242 until mine comes in.

He explained to me that my boat currently runs well over 55mph at 7600rpm and it's because the tach.

Any thoughts....

I almost forgot, @William Hamlin, WELCOME! And congratulations!

I think the salesman info may not be completely accurate, but who cares. Sounds like you have got yourself a very nice boat! Those SX190s are a ton of fun, really perfect for a family with kids around. Easy to store and trailer. I used to have one and miss her dearly!

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[William Hamlin]

Thanks. Really is a great boat.

The 2 Tech's that tested the boat before delivery said they called Yamaha because they were confused why it was going so fast and asking if it was the tach and didn't get any sort of definitive answer. "the tach that goes in your boat will be here is 7-10 days".

Regardless she's an amazing machine. Looking forward to tomorrow.

 

[swatski]

Thanks. Really is a great boat.

The 2 Tech's that tested the boat before delivery said they called Yamaha because they were confused why it was going so fast and asking if it was the tach and didn't get any sort of definitive answer. "the tach that goes in your boat will be here is 7-10 days".

Regardless she's an amazing machine. Looking forward to tomorrow.

Sounds like she's a keeper!!!

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[itsdgm]

Welcome to the site and congrats on your new boat. Sounds like she's running well!!

 

[d_coyne1984]

If it does turn out the tach somehow does have something to do with a normally 43-44 mph boat running 49, that will be the best bang-for-buck performance mod in the history of boating! I could go for a $200/5mph increase on my 192. 55 sounds like fun!