wiring for dummies

[oldboatguy]

Can someone explaine the tachometer types
3 4 6 10 12 20 pole ?????????????
can you hook a tach to outbord with out a generator?
what does the pole represent....
what type would a 1984 70 hp 3 cyl evenrude outboard use
and where does it wire to on the powerhead....

 

[flabum]

Re: wiring for dummies

Outboard tachs run off the charging system coils. there are different size stators that is why the tach has different settings. Your engine should be a 6 pole if you have a charging syatem on it (with tha motor you do have a charging syatem unless someone removed the rectifier). The sensor wire is a gray wire in the engine harness that is hooked up to one of the yellow wires comming out of the stator.

There are some tachs out there that hook up inductively such as the Tiny Tach, but the attaching wire is only about 8 -10 feet long.

 

[HighTrim]

Re: wiring for dummies

To try and explain it simply, tachometers read off the alternating pulses from the stator. Any of the leads from the stator charging portion can be used for the signal. The designated tach signal wire is merely attached to one of those. Tachs have rotary switches on the back that set it to different numbers of coils in the charging circuit, times two because there is a positive and negative pulse for each coil for each cycle. Tachs measure pulses. That being said, you need a tach that has the setting that you need designated on the rotary switch. These sites may help,


http://ww2.tflx.com/pdf/obtach~1.pdf
http://ww2.tflx.com/PDF/99320.pdf

 

[R.Johnson]

Re: wiring for dummies

If you had a stator in your hand, count the poles', each copper winding around around the green colored laminated protustions on the stator ring, divide by 2, this would be the pulse

 

[flabum]

Re: wiring for dummies

If you had a stator in your hand, count the poles', each copper winding around around the green colored laminated protustions on the stator ring, divide by 2, this would be the pulse

Some stators have three wires comming out of them, in that case you would divide by three,

 

[oldboatguy]

Re: wiring for dummies

thanks for the help