Tach issues

[V153]

That's cool as long as I don't smoke the rectifier! (if it isn't already toasted)

Sounds like yers is workin. Long's it's 13v or so at idle you're good. As rpm's increase it should climb a lil, but not a whole lot.

[Rosscoe]

So it appears I can rule out the rectifier.
Guess I'll order a new tach.

[thedeuceman]

if you want i can look ans see if i got something tonight

[Rosscoe]

if you want i can look ans see if i got something tonight

That would be great...or if I can figure how to connect the one I have. I might mess with it today or go work. Depends on the weather.
Thanks Joe

[V153]

Yo Ross. Might be worth asking over on the antique outboard forum about correct wiring for that tach?

[Rosscoe]

I haven't been on many other forums.
In any case, I think this one may be bad too. I connected the obvious ones (gray, black) and connected 12v to one of the open terminals and started the motor. Tach went to 3k so I thought I would try the other one and it read the same thing. I noticed after I shut the motor off it was still sitting at 3k. Banged on it some and it went to 4k. Its stuck up in that area.
I also verified once again that the battery is charging. Went up into the 14v range when revved. I removed my old tach and banged on that and couldn't get the needle to move at all. May be it didnt like the winter I left it outside, or it didn't like my humid barn. Hope that trend does not continue because if that is the case, I've got the whole herd in the barn possibly doing more harm than good?
I'm ordering a new tach. This one was installed when the guy I bought the motor from rigged the boat. Its about 10-11 years old. Faria brand.

[V153]

Not sure about Mercs, but on a OMC when you key the ignition "on". The tach should zero.

[Rosscoe]

Yeah that sounds like what I have been reading. It was at zero before I turned the key on. It went to 3k, stayed there, key on or off.
I was hoping to use this one in the 61 with the Evinrude, but that's a ways off. I'll hang on to it just in case.

[Rich_V174SS]

If the tach has an adjustment screw on the back for setting the number of poles or cylinders sometimes the contacts inside get mucked up. I take a screw driver and rotate the screw back and forth quickly a number of times to improve the contact, then set it to the required position.

[Rosscoe]

Argh
2 seconds late. I just ordered one. Oh well, I'd still like to know if the old one is good and will try that. I have enough boats, I am sure I can use it. Speaking of that, since I never had any instructions, how does one determine that setting? Number of poles?

[V153]

I bleve the "P" stands for 'pulses'. Not 'poles'.

12 pole = 6 pulses.

[Rosscoe]

So my current tach is set at 5. Not sure of the correlation there with a 4 cylinder.

[Rich_V174SS]

If the tach is used with an I/O engine you'd set it to corresponding cylinders like 4, 6, or 8. When used with an outboard it's usually 12 pole alternator.

[V153]

So my current tach is set at 5.

Should be set at 6. There's no correlation to number of cylinders.

[Rich_V174SS]

Some tachs have numbered settings like 1 thru 4 or 5 and a small tag indicating what each number corresponds to. As an example (but not necessarily an accurate depiction) 1=4 cyl, 2=6 cyl, 3=8 cyl, 4=10 pole alt, 5=12 pole alt.

[dorelse]

Some tachs have numbered settings like 1 thru 4 or 5 and a small tag indicating what each number corresponds to. As an example (but not necessarily an accurate depiction) 1=4 cyl, 2=6 cyl, 3=8 cyl, 4=10 pole alt, 5=12 pole alt.

I remember the old Force's had a 20 Pole Tach...which is hard to find!

And, yes, that's totally unrelated to your issue Ross...sorry!  lol!

[Rosscoe]

Some tachs have numbered settings like 1 thru 4 or 5 and a small tag indicating what each number corresponds to. As an example (but not necessarily an accurate depiction) 1=4 cyl, 2=6 cyl, 3=8 cyl, 4=10 pole alt, 5=12 pole alt.

That is pretty much what the table on the back of the tach looks like so if its a 12 pole alt, 5 is correct. I wouldn't think it could have moved on its own. You have to use a small screw driver and push it in so I believe it is in the same spot it was all these years
5-12
I am going to mess with it like you said Rich and hook it back up and see what happens.