extr wires and tach install???

[fallguy666]

I am wanting to install a tach on my 86'350x.I have some extra wires? Around the headlight wiring.my question is,are these the wires for the tach? Or are hey for something different?

[jeswinehart]

I am wanting to install a tach on my 86'350x.I have some extra wires? Around the headlight wiring.my question is,are these the wires for the tach? Or are hey for something different?

They are used with the jumper wire loop supplied with speedo's or tachs, sub harness as Honda calls it.
Interesting post from Blazer1 a few years ago (also has your wiring info to).
http://www.3wheelerworld.com/showthread.php/51311-Honda-Tach?highlight=350x+tach+wiring
What kind of tach you thinking on using ???

john

[fallguy666]

Don't know.Lol.I read that thread last night on a search mission.didn't really go anywhere.I don't want one of those small ones that are hard to see.I really want like a two inch one.I found some on eBay for scooters? I'm pretty sure they are single cylinder TACHS.gonna bite the bullet and order one and try to be wire it using the diagram in that other post.or do y'all have a better idea?

[wonderboy]

To add to what John wrote, the two free wires in your harness are:
White/Yellow: constant hot lead (comes straight from the voltage regulator)
Brown: switched hot lead, comes on with the headlamp switch in the on position (doesn't depend on high or low on the dimmer switch)

To install your tach, Honda will provide you with a special wire harness that lets you tap into the coil trigger wire (black/yellow) right at the coil terminal. You'll bring this extra wire up to the tach to feed it the RPM signal it needs to run.

John posted the link to the exact wiring instructions. Just match colors, plug and play.

EDIT: I read your follow-up post and realize you aren't using a Honda OEM tach. Basically though, given the three circuit described here (constant hot, switched hot, and a RPM pulse line) you should be able to adapt almost any tach.

One detail to keep in mind is that a 350X fires the spark plug on EVERY revolution of the motor, even though spark is only required every other stroke. If you get a generic automotive tach, there is usually a setting for the number of cylinders. You'll have to think about what setting to use to get proper readings. (that is assuming it will work at all, I'm not familiar with adapting one to ATV use).

[fallguy666]

That would be awesome if you could get that link!!! Do I have to use Hondas harness for the signal wire or can I just tap into it with my own?

[jeswinehart]

You can wire into your own using your own design of wiring.
The trigger wire as I call it) is the single 16 or 18 gauge wire coming from stator area to the tach, that is the lead you want to feed the tach "pulse" with. Most anywhere that sells wire terminal ends has the piggy back terminal.
I bet I still have a dozen on hand,,,,
Drag speacilties have a affordable tach and they perform some what okay from my exsperiance (revs fall off slow).
They make for 2 stroke and 4 stroke so be very alert as to which one you get.
http://www.ebay.com/sch/i.html?_dmd=3&_dcat=10063&Brand=Drag%2520Specialties&_nkw=mini+tachometer

[wonderboy]

Sorry about the edit in my post. I initially said I'd dig up the link, but then I realized that the one I was talking about was the one John posted in the post directly above mine.

There is nothing too special about the Honda harness to tap into the coil wire, other than it has both a male and female connections so that you can avoid cutting and splicing of wires. The Honda harness is plug and play. The key element of wiring in any tach is something to feed it the pulses firing the coil, as this allows it to calculate the RPM. So, tapping into the black/yellow (read black wire with yellow stripe) is the key.

If you have to cut and splice, and if you aren't familiar, ask for instructions here. There are good ways and bad ways to splice into wires...

[fallguy666]

I'm pretty good at splicing/wiring/soldering stuff.Lol.I've been a mech most all my life.everything from bicycles to to earth movers.but,I learn something new everyday!! Thanks guys this is just the info I was seeking!!!!