Mech Tach to electrical?

[Guest]

Is it possible to put an aftermarket Speedo/tach on a 79 gs750 that has an electrical tach? Any help is greatly appreciated!

[salty_monk]

Depends on the tach. Usually you just tap in to the trigger wire for the coils & set the tach to the correct setting.

Because we have a wasted spark system this means the coils trigger twice every cycle, I can't remember what setting I used on my Koso XR but it wasn't a Four cylinder four stroke...

[Crankthat]

Know i have read a similar thread before, cant recall if was on this site or another. The info that i most gleaned from that thread?
Going along with what salty monk said and adding to keep your tach on or borrow one for set up of your electrical tach to adjust for correct setting.
In the thread i read they were having trouble with set up and using the original one for set up of electric was the most accurate way.

[trippivot]

electric tachometers are either single fire or double fire. ( single impulse/double impulse) what ever terms they use you need a double fire unit.. positive,negative and the ign lead wire goes to the negative side of 1 of your large ignition coils

single impulse systems are V8 automobiles some autometer units or harley anything DO NOT WORK

80's,90's GSXR all work for your GS. ZX6,7,9,11, EX 250,500 all work. I had a cool ZN700 dash on a katana once, and a radian set up on a gpz 750. most all sensors will interchange to operate the dash lights. amazing how the speedo drives are similar ratio too.

[NBraun]

Thanks! That really is great info!

[greg78gs750]

electric tachometers are either single fire or double fire. ( single impulse/double impulse) what ever terms they use you need a double fire unit.. positive,negative and the ign lead wire goes to the negative side of 1 of your large ignition coils

single impulse systems are V8 automobiles some autometer units or harley anything DO NOT WORK

80's,90's GSXR all work for your GS. ZX6,7,9,11, EX 250,500 all work. I had a cool ZN700 dash on a katana once, and a radian set up on a gpz 750. most all sensors will interchange to operate the dash lights. amazing how the speedo drives are similar ratio too.

very good info, indeed. i was considering a trail tech for a replacement this winter, i will have to look for some of these cheaper! thank you sir!

greg

[Roger P.]

electric tachometers are either single fire or double fire. ( single impulse/double impulse) what ever terms they use you need a double fire unit.. positive,negative and the ign lead wire goes to the negative side of 1 of your large ignition coils

single impulse systems are V8 automobiles some autometer units or harley anything DO NOT WORK

80's,90's GSXR all work for your GS. ZX6,7,9,11, EX 250,500 all work. I had a cool ZN700 dash on a katana once, and a radian set up on a gpz 750. most all sensors will interchange to operate the dash lights. amazing how the speedo drives are similar ratio too.

That would give you that neato pushbutton voltmeter option. I wonder if a GPz tach is the right size to fit into an 1100 cluster?

[John Kat]

You can also use a GSXR 750/1100 tachometer by simply connecting it to one of the ignition coils ( the switched side).
I did it with both a first generation ( 1987/88) and second generation GSXR ( 1989/90) without any problem
Here's a picture:

[greg78gs750]

hi again john,

what kind of connection is going on in the back of that thing? did a pigtail come with the cluster? also, do those have gear position indicators? that's one thing i've been trying to figure out with the trail tech, i have planned to fabricate a dashboard for it incorporating the indicators, i know a guy with a cnc mill... thanks again john!!

greg

[Billy Ricks]

I'm using GSX-R gauges too. I spliced mine into the GS harness. You have three wires; constant power, trigger from a coil, and ground. No gear indicator, just idiot lights including one for neural. They all have to be massaged into the harness.

[John Kat]

hi again john,

what kind of connection is going on in the back of that thing? did a pigtail come with the cluster? also, do those have gear position indicators? that's one thing i've been trying to figure out with the trail tech, i have planned to fabricate a dashboard for it incorporating the indicators, i know a guy with a cnc mill... thanks again john!!

greg

Hi Greg,
it's relatively easy to wire the GSXR cluster in place of the GS 1000 one.
First: you reuse the existing connector that you cut off from the GS 1000 cluster by leaving 2" of wire.
Second: you solder all the wires that have the same color code from the GSXR cluster to the GS 1000 connector .
Third: you use the "fuel level" wire on the GS Connector to relay the "tachometer signal". This wire must be rerouted to the ignition coil on the switched side instead of going to the fuel level sender.
It's magic when you turn the ignition key on and all the lights come on on the new cluster
And when the engine runs and the tachometer works it's like Christmas

Hope it's clear?

[greg78gs750]

thanks billy and john. yeah, i have been jonesing for a working tach for a while now.... I know i am being a baby about the gear position lights, it's just soo convenient for me. thanks again guys, when i get around to doing this this winter i will post up some pics! also on the agenda, twinpot mod, new front tire, and maybe some cartridge emulators.... like a whole new front end!

greg

[Tazman001]

electronic tach

How about one off a late 90's bandit? Easily done? Really like those chrome ones from that year/model.