Tachometer

[hjbutler]

Hello everyone! After working intermittently for a few months, the tach gauge on my 1994 Adventure 20 has stopped working at all. I'm trying to think of the most efficient way to troubleshoot this, considering it could be the gauge itself, bad connection somewhere, or perhaps no signal coming from the engine. Is there a quick way to see if it is simply the gauge being worn out?

 

[Fishtales]

Those are some older models. I'd see if I could find the manufacturer and search the net to see if any documentation exists.

 

[seasick]

In the picture the tack is reading about 650 revs. Is it stuck at that number?
If so and it doesn't change when powering on or off, I would suspect that the gauge is bad.

 

[glacierbaze]

I would have guessed that the gauge cluster is older than 1994. What brand of motor came on the boat?

 

[Legend]

I just had to replace a tach gauge that was installed 7 years ago during a repower. The gauge just went blank. I have twins so it was easy to check by swapping the plugs with the other tach. Easy to replace just take a picture of the wire connections and plug in the new one. the gauge is a little over $300 .

 

[hjbutler]

Hello All, to answer the questions asked:

The tach goes to zero when the key is turned on. And there it stays.

The engine is a Mercury 200 "Black Max" and I think all the gauges and controls are from Mercury. Everything is original from 1994. I'd love to have new power but that would cost more than I paid for the whole boat...and the old Merc runs very well!

 

[seasick]

Do you know the serial number of the motor?

The fact that the tach goes to zero when you power on tells me that the gauge may be OK but the tack signal from the motor is not. I can't look at parts or wiring without the serial number.

 

[hjbutler]

Hi, thanks for your reply. The SS# is 0G051563 (I think the G is the only letter.) 2.5 L Offshore 200.

 

[seasick]

I'm not 100% sure but if the motor is a 2 stroke with fuel injection, the tack signal comes from the Electronic Control unit and is a green color wire. I don't know if this info is going to help .

 

[hjbutler]

Hi, it's a 2 stroke with oil injection but with carbs, no fuel injection. It's pretty low tech. But I'll look for the green wire.

 

[seasick]

If y0u have an ignition coil, the signal comes from that. Probably the coil that fires cyl 1.