Tachometer Basics

[boomtime]

Ive been doing a lot of reading about tachometers around here and also on the internet, ebay, etc.
I feel like im getting mixed messages about these because some engines have actual alternators and some have electronic ignition and some have rectifiers.
In my situation i have a rectifier and as best i can tell i dont have an alternator so where does this leave me as far as tachs? The teleflex install guide says O/B w/ alternator but reading around it sounds like its ok to hook this up to the rectifier with the right pulse setting...is this correct?
I dont want to blow up the new tach when it arrives.
Any ideas or a list of the 2 or 3 types (maybe more) of tachs?

 

[Silvertip]

Re: Tachometer Basics

I don't know of any modern outboard that does not have an alternator. That's what generates the current that charges the battery. Because you have an alternator, you need either a rectifier/regulator combination or a rectifier. Either one changes the AC current created by the alternator to DC required by the battery and electrical system. The difference between a rectifier and rectifier/regulator is that the regulator has additional circuitry that keeps the charging system within certain limits. So your confusion is over terminology. Regardless what outboard you have, the ignition system has nothing to do with the tach as its driven by the alternator. Follow the instructions and you will be good to go.

 

[boomtime]

Re: Tachometer Basics

is the alternator built into the motor like a magneto? similiar to my motorcycle (stator) on the end of the crank? because there doesnt appear to be an actual alternator like a car would have.

 

[Silvertip]

Re: Tachometer Basics

Yes. Magnets in the flywheel pass over the stator as the motor runs. Been that way for decades.

 

[boomtime]

Re: Tachometer Basics

Yes. Magnets in the flywheel pass over the stator as the motor runs. Been that way for decades.

excellent so like i asked...in this case the alternator is actually integrated into the motor and its dynamics. thanks for your help.

P.S. - your sarcasm was priceless, thanks again.

 

[Silvertip]

Re: Tachometer Basics

Sarcasm???? I guess it has come to pass that one must answer with "yes" or "no" and that any further clarification is considered being rude.

 

[jtexas]

Re: Tachometer Basics

Sarcasm? Interesting comment from a person who said, "...i have a rectifier and as best i can tell i dont have an alternator...." We didn't make fun of you because it was plain that you don't know what an alternator is, or a rectifier, or what they do, and why either one without the other would be useless as a milk bucket under a bull.

 

[walleyehed]

Re: Tachometer Basics

As a Moderator, I have to agree with jtex and silvertip....you asked the question and got an honest, technical (and correct) answer.
There was no sarcasm in that answer and I would suggest that "IF" you do not know the components of your project well enough to know if you're getting a good answer or not, BUY A MANUAL and confirm....
I would think you owe Silvertip an apology.

 

[Silvertip]

Re: Tachometer Basics

No apology necessary but I am puzzled by what you considered sarcastic. Depending on what year, make and model of engine you have, the tachometer connection may already be provided on the control box so there is no need to run the wire back to the engine since the wire is already available. You will need the tach cable that runs from the connector to the tach. Boat safely.

 

[boomtime]

Re: Tachometer Basics

sorry for the misunderstanding i was joking.
my comment was in reference to the statement "been that way for decades" lol because ive only been around for 2 myself.

im suprised by how many other replies the thread got after i said that and how quickly, maybe i should stir the pot more often to get more attention :redface:

so anyway i hooked the tach up today and shes workin good hopefully the wind lays down tomorrow and i can try to make the reef.