Bad reading on the tachometer...

Lake_Bum

My boat is a 2000 Captiva 232, with the 350mag and Bravo lll outdrive.  I had very irregular readings on the tach when I test drove it.  I ended up buying it, and had to winterize it once I got home, so it's tucked away for the winter now! I was getting readings off the charts according the the gauge, as in buried above 6000 rpm's even at cruising speeds, and from my speeds, and sounds on the motor I would guess it at 2800 "actual".    
Any clues as to how to address that issue, once spring rolls around?  The readings were normal at idle, then would be all over once on plane....... 

Handymans342

Replace tach

Lake_Bum

Handymans342 said:

Replace tach

Hahahahaha  I don't know why I found that so funny, but it was!  Sometimes things ARE that simple 

frenchship

Is it a Faria gauge?

Lake_Bum

frenchship said:

Is it a Faria gauge?

I believe so. I know it is a factory gauge, but it is currently tucked in until the snowstorm subsides.....
I'll probably just remove/replace it when I find the time to install my fishfinder this winter. I was just hoping for a little insight from someone that has encountered the same problem with their tach. 

LaRea

It's one of the most common problems.  In some cases, people have found grounding or wiring issues that caused it, but that's rare.  

You could also look at using VesselView Mobile to see engine RPM (and other data).  It's a bluetooth transmitter that plugs into your engine and uses your cell phone or tablet to display real-time data.  $275 from Mercury.  

Ian

Mine do that too, sometimes just a tap will fix, other times the demons leave the gauge themselves and all is well until next time. From many other comments in the forum it seems to be a Faria trait.

Stodge

Some tachs have a switch on the back for 6 cylinder and 8 cylinder.  Might be worth a look to see if that switch is there and out of place.

A smartcraft tach would be nice, but I don't think Mercruisers had smartcraft before 2002.

Bad ground is always a likely cause.  If you have access to an automotive diag tool with a tach (I have one that looks like a VOM but has tach and dwell), might want to try reading the RPM with it using the wires at the gauge.

Good luck.

Handymans342

Stodge said:

Some tachs have a switch on the back for 6 cylinder and 8 cylinder.  Might be worth a look to see if that switch is there and out of place.

A smartcraft tach would be nice, but I don't think Mercruisers had smartcraft before 2002.

Bad ground is always a likely cause.  If you have access to an automotive diag tool with a tach (I have one that looks like a VOM but has tach and dwell), might want to try reading the RPM with it using the wires at the gauge.

Good luck.

Stodge, what do you use if it is a 4 Cyl diesel? LOL

Stodge

A metronome.....

zaverin1

Maybe a 4cyl setting and a gage with a ✊ mode 

reneechris14

Faria gets 125 a tach for repair plus shipping.that does not mean it will a corrected reading but it looks good . its on there  Web sight Faria beebe.com.

reneechris14

Handy it's 4,6,8 but only for us gasser.you smokey boats don't have ignition they just run forever . 

Handymans342

reneechris14 said:

Handy it's 4,6,8 but only for us gasser.you smokey boats don't have ignition they just run forever . 

You are smoking too much smoke

zaverin1

✊ it's not smoke anymore
it's called clear
the real truth oil

Lake_Bum

Thanks for the input guys! 

pault1216

Corrected mine by cycling 4-6-8 switch several times and tightening/cleaning wire connections. This worked on 2 of my boats. Good luck.

69fastback

My tach on my 232 is crazy too. It's just all over the place. Maybe I'll fix it this year. 

SeaHare

mine are all over too.. faria gauges. cycling 4-6-8 helped. Also a good whack with my pointer finger knuckle puts it back in place

rasbury

I don't worry about it to much....I just go by the sound anyway and the feel of the boat. If I had twins I'd think it be more important.

Lake_Bum

rasbury said:

I don't worry about it to much....I just go by the sound anyway and the feel of the boat. If I had twins I'd think it be more important.

I definitely pay attention to the sound as well, but I am OCD with anything that isn't working perfectly on my boats.  If I ignore one thing, that leads to another 

SeaHare

Actually with twins, you have the sync gauge, which has always been accurate. Between the two tachs, one of them is always right, then just sync the engines... with experience, sound is all you need

reneechris14

I like all things to work so I will pay,and hope they last for a while.or a VV7 maybe next.

Stodge

I only kept the sync and the multi-gauges (because they show fuel).

reneechris14

Nice and clean,good work

reneechris14

Sent out both tachs and sync gauge in Nov. and they sent new gauges back today.That's assome but the tachs will be zero hours.well I guess I will know how many hours I put on the boat.+300 port +296 starboard.

J3ff

How much did they charge you? My volts dont work either. 

reneechris14

To much 125 each tach 50 for 2"gauge.can get cheaper from greatlakes skipper but did not match. Faira Beebe online,there in Uncasville