Tachometer question

[DWABoat]

I have a 2001 280 Sundancer with twin 4.3L EFI (throttle body injection) systems.

All the systems and engines run great.
my question is about the tachometers. I am dealing with the typical Sea Ray OEM tach issue with the flailing tach.

The starboard tach, I believe, is pretty accurate based on engine sound.

The port tach is not even close and will change by a few thousand on its own. I do not rely on it at all.

Now...these are not critical to me. I am a “slow-boater” and only run my baby at just over planing speed. I never WOT or even close. I match throttles based on the analog load balance meter. Not exact, but I get by.

I would like to get some reliable tachometers, but am not ready to make a huge investment in SR tachs. Upgrading to some computerized monitor system is out of the question, at this time.

Can I install some basic analog automotive tachometers that wire to one side of the ignition coil? Would those work? Would they interfere with some other system dependent on the OEM tachs? I realize they would not look like the other gauges, but this would only be for one season. I can install a couple of mid-grade tachometers pretty cheaply while I decide a long-term solution. Anyone have any insight?

 

[Lazy Daze]

You actually may be able to take care of this for free. On the back side of the tach, rotate the little switch around and make sure to come back to the "6" setting. Tachs can be used with different sized engines and that switch is what you change for that. Over time, the switch gets dirty and you need to clean the contacts by exercising it a bit.

FYI... this isn't a "Sea Ray" thing - it's a "tach" thing and can happen in any brand boat.

 

[R-and-R]

I went for 2 seasons like that because I wasn't that concerned about tach accuracy.
But I finally got around to doing exactly what Lazy Daze recommends. They work great now. I've compared them with an electronic tach and they are spot on.

Easy job.
Good luck.

 

[Express 390]

I have a 2001 280 Sundancer with twin 4.3L EFI (throttle body injection) systems.

All the systems and engines run great.
my question is about the tachometers. I am dealing with the typical Sea Ray OEM tach issue with the flailing tach.

The starboard tach, I believe, is pretty accurate based on engine sound.

The port tach is not even close and will change by a few thousand on its own. I do not rely on it at all.

Now...these are not critical to me. I am a “slow-boater” and only run my baby at just over planing speed. I never WOT or even close. I match throttles based on the analog load balance meter. Not exact, but I get by.

I would like to get some reliable tachometers, but am not ready to make a huge investment in SR tachs. Upgrading to some computerized monitor system is out of the question, at this time.

Can I install some basic analog automotive tachometers that wire to one side of the ignition coil? Would those work? Would they interfere with some other system dependent on the OEM tachs? I realize they would not look like the other gauges, but this would only be for one season. I can install a couple of mid-grade tachometers pretty cheaply while I decide a long-term solution. Anyone have any insight?

The long term solution is to replace the tach's with Aetna Engineering Digital Tachometers, This will end the problem once and for all.Very easy to install, And they have a few different styles. Worth the investment ! Im a little nuts and did a dash do over but you get the idea . lol Mine were a lot older the issue just kept happening !

 

[stephens013]

Lazy Day has the solution. The good folks at Flounder Pounder do much the same thing. Make the internal sweep hand clean off its contacts. I'm told that 9 times out of ten it brings old, irratec tachometers back from the bring. Hey; it's cheap and it keeps the integrity of the boat.

 

[Express 390]

Lazy Day has the solution. The good folks at Flounder Pounder do much the same thing. Make the internal sweep hand clean off its contacts. I'm told that 9 times out of ten it brings old, irratec tachometers back from the bring. Hey; it's cheap and it keeps the integrity of the boat.

Hey it's worth a shot!

 

[DWABoat]

Thanks for the replies.
Express, that is one impressive display! That is my ultimate destination, just not in the budget right now. If I end up swapping tachs, digital it will be.

I will try the twist selector technique, I have read about that before. Hopefully that solves the issue. I feel it will since the errant tach is sensing variation in pulses because it moves with the throttle. Something is still working inside it.

So, back to my original question: if I ultimately install another tach, can I wire it outside the Sea Ray wiring harnesses directly to the coil like, say, an aftermarket tach on a 68 Camaro?

I don’t know if unplugging the OEM Tachs will upset the closed loop operation of the ignition computer in a relatively basic system on a 2001.

I can get a couple of wires back to the coils, pretty simple, as long as I don’t fry some module if I do it.

 

[Golfman25]

The long term solution is to replace the tach's with Aetna Engineering Digital Tachometers, This will end the problem once and for all.Very easy to install, And they have a few different styles. Worth the investment ! Im a little nuts and did a dash do over but you get the idea . lolView attachment 94355View attachment 94356 Mine were a lot older the issue just kept happening !

So question for you. Do those fluctuate with every 1 rpm change? Or do they settle in. For example, my normal tack just sits at 3000 rpm and doesn't show every minor fluctuation.

 

[Express 390]

So question for you. Do those fluctuate with every 1 rpm change? Or do they settle in. For example, my normal tack just sits at 3000 rpm and doesn't show every minor fluctuation.

They just sit where you set them they are awesome ! They are accurate to 1 rpm. In fact they are so accurate they claim you don't need a sync gauge but i hooked mine up anyway there's a module behind the dash to calibrate the sync gauge to the new tach's

 

[KevinP]

You actually may be able to take care of this for free. On the back side of the tach, rotate the little switch around and make sure to come back to the "6" setting. Tachs can be used with different sized engines and that switch is what you change for that. Over time, the switch gets dirty and you need to clean the contacts by exercising it a bit.

FYI... this isn't a "Sea Ray" thing - it's a "tach" thing and can happen in any brand boat.

I have the same issue on a 2001 310DA. Apologies in advance for asking a NOOB question, but how do you pull the tach out from the instrument panel?

 

[GnrlPatton]

I have the same issue on a 2001 310DA. Apologies in advance for asking a NOOB question, but how do you pull the tach out from the instrument panel?

On mine, it's easier to remove the panel that the tach is housed in. The whole thing comes out, and then you can remove the brackets from the back. For what you are trying to do, just pull the panel out and you will have access to the little pointer knob that LazyDaze calls out. Take a screw driver and rotate the knob fully several times each way, and then be sure to put it back on it's original setting. I did this with mine last year and my tachs have been solid, no more jumping around.

Kevin

 

[bobeast]

I have the same issue on a 2001 310DA. Apologies in advance for asking a NOOB question, but how do you pull the tach out from the instrument panel?

You don't actually need to remove the tach in order to exercise the switch. Just un-screw the panel and lift it out far enough to get your hand in with a small screwdriver.

 

[DWABoat]

Sooo...back to my original question!
Lots of great information so far, but nobody has addressed the way to wire an aftermarket tach to my older, throttle body FI with a separate ignition coil.

 

[techmitch]

Sooo...back to my original question!
Lots of great information so far, but nobody has addressed the way to wire an aftermarket tach to my older, throttle body FI with a separate ignition coil.

How many wires on the tach and what colors are they?

 

[DWABoat]

How many wires on the tach and what colors are they?

I have not purchased new tachs yet.
I am going to try the technique listed above to save my original tachs.
If my attempts fail, I am wondering if my system will accept a standard tach like the type wired to the ignition coil.

 

[techmitch]

I have not purchased new tachs yet.
I am going to try the technique listed above to save my original tachs.
If my attempts fail, I am wondering if my system will accept a standard tach like the type wired to the ignition coil.

Copy. Analog tachs are pretty simple. Power, ground, input signal (from coil neg. side) and instrument illumination.
Red, black, gray/green, blue respectively.
Don't know any reason why you can't run both, worst case, a diode could be added.