Topic: Wiring Electronic Tachometer Up-Grade Instructions/Directions

[Kafes4ever]

Hey CB'ers:

Hello:

I'm in the process of wiring up a Katana electronic (needle gauge)
tachometer to my 1978 cb750K SOHC.  I'm presently running a
Dyna-s Electronic Ignition System.

There are three leads on the new tach:  Black, Gray and Orange.
I believe (been told) the Orange is the signal lead.

I need to know where to hook into the pulse signal of the ignition system.

Does anyone out there have this information?  I sure would appreciate knowing how to do a proper job and not blow this up-grade, literally!

Thanks,

J Parzino 

[nickjtc]

Sorry, I can't help, but ooooooh. Nice bike, mister.

[tsflstb]

Very nice bike.

I went through this with an aftermarket tach from Summit.  It had three wires - one constant 12V, one switched 12V and one that taps into the coil trigger from your Dyna S.

http://forums.sohc4.net/index.php?topic=32589.0

[kpier883]

I don't know the answer to your question, but I would like to know about the tank on your bike.  How many gallons, what had to be done to make it fit, and what did it come off of?

[Joel]

I don't know the answer to your question, but I would like to know about the tank on your bike.  How many gallons, what had to be done to make it fit, and what did it come off of?

x2.  It looks fantastic on there.

[crazypj]

Orange is 12v in
 black is ground
gray is trigger to points/coil wire.
 Is it 11,000 or 11,500 redline?
 11,500 comes on 93~97 Kat 600
PJ

[Kafes4ever]

Orange is 12v in
 black is ground
gray is trigger to points/coil wire.
 Is it 11,000 or 11,500 redline?
 11,500 comes on 93~97 Kat 600
PJ

Thanks, PJ... My Kat Tach face shows the red-line start @ 12,000 and goes to 14,.000.  I'll plug the wiring in as you suggest.  If this works you get the Muriel.  JP

[crazypj]

Its a later model GSX-R one then and not a Katana.
Doesn't matter though as the wiring is the same.
PJ

[Kafes4ever]

PJ,
I just went and wired it up as you indicated... This tach has three leads; Blk w/white stripe, Blk w/red stripe and Orange w/green stripe.  I hooked the Blk/R to -Ground and the Orange/grn to +12V and I hooked the Blk/W to Signal.  However, no luck! I get NO read out and two of four cylinders ground out!  This is becoming discouraging. Initially I had the Orange hooked into the signal and did get a signal/read-out but the same cylinder/grounded coil problem as with your instructions, no mater which signal lead I use from either coil.  I have heard that there is a possible tach converter/adapter unit that might be needed in the circuity to make things work properly.  Any knowledge to share on this sinerio?  JP

[Joel]

This thread discusses what're your thinking of, I believe.

http://forums.sohc4.net/index.php?topic=32589.0

Since the SOHC4s use a wasted spark system, the triggering isn't the same as a standard 4-cycle.

I don't know if that has anything to do with your grounding problem or not though.

[crazypj]

Suzuki Blk/W is ground, Honda = green
Suzuki O/G power in, Honda = Black
 Bk/R trigger, = points wire
 thats not the colours you said in first post, what happened to the Bk, Gy, O?
 you have more than one Suzuki tach?

[Kafes4ever]

PJ:
Sorry, I had them wrapped for months identified them from memory... poor as it is at times.   I un-wrapped them and discovered the true colors are really as I last stated.  Someone has also offered that there is a Dynatek Tach Adapter needed to hook into the circuity for proper performance.  Thread is avaiable @

http://forums.sohc4.net/index.php?topic=32589.0

Looks like a simple solution and I'll be giving it a try soon.  If anyone out there has the schematic or a list of parts/resistors/diodes needed, I'd sure like to have a copy??

Thanks for your help man!  JP

[crazypj]

you shouldn't need a tach adapter as the Suzuki Katana also uses crank mounted trigger and a wasted spark.
 
 I have a Katana tach here, I'll try it on my Yamaha (crank mounted signal generator) Except for the 350F, all the other Honda's I have are cam mounted points and run at half speed so would need an adapter to get crank speed signals.
PJ

[yellowbirdrs]

Any updates on the Katana tacho wiring?
I would love to upgrade the stock tacho.

[crazypj]

Dunno, I had forgotten all about it. (2008 thread)
Never did hook mine up to Yamaha, not even sure where it's stashed now