Kawasaki Z1000 electronic tacho

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Basketcase

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Anybody fitted one of these after market electronic tachos?

I bought one cheap years ago because they are almost identical dimensions to the ND but I never installed on my SF2.

The original Z1000 wiring uses a ghost spark off two points sets to fire four cylinders every two revs.

The possibility is that this tacho (being for a Z1000) is calibrated for a single spark sensor, which produces one pulse per rev (counting the ghost). This would need two Lav 750 pickups combined, one from each spark wire sensor.

My bike is not running at the moment and any information would save me having to set up an electronic signal generator on the bench.

Cheers
Rob

(edit: just found some information confirming this is designed to sense just one points wire)
 

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Hi Rob,

I think I did use a similar gauge on my Jota, it just came off a Yamaha. 2 main things to be sure you can use it on the Laverda:
-must be from a carb operated model (injections have different signal and tachos can not be connected to the coil, they can not handle the high voltages there.
-if the bike it came from has a 4-cylinder engine that is run by two twin coils, it will fit.

HTH
 
Laverdalothar said:
Hi Rob,

I think I did use a similar gauge on my Jota, it just came off a Yamaha. 2 main things to be sure you can use it on the Laverda:
-must be from a carb operated model (injections have different signal and tachos can not be connected to the coil, they can not handle the high voltages there.
-if the bike it came from has a 4-cylinder engine that is run by two twin coils, it will fit.

HTH
Click to expand...
Thanks for your reply Lothar,

I found a vendor website saying the tacho is specifically for the Z series. These use two points, each with twin coils.

Instructions say the sensor wire must have a few turns wrapped around the points wire to one coil primary. Therefore it gets a weak low voltage signal by induction pickup.

Cheers
 
Innaresting thread. And nice looking tacho. I'm yet to test the ZXR250 tacho on my bike, but it triggers from an Ignitech box, so hopefully the high degree of setupability will make it work.

If the one you mention works from a signal wire wrapped around a points wire then would it also theoretically work with any power-to-coil wire?
 
piranha-bro2 said:
If the one you mention works from a signal wire wrapped around a points wire then would it also theoretically work with any power-to-coil wire?
Click to expand...
That probably won't work Quentin. It needs to connect to the other side of the coil. The "power to coil" wire is always at around 12V so there is no signal to be found there. You need to connect to the other side of the coil primary circuit. The wire that goes from the coil to the points switches between 12V (points open) to zero Volts (points closed) so it has an approiximate square wave signal that the tacho can read. But before connecting the tacho pickup wire to the bike's electrical system, it might be a good idea to confirm that the tacho will handle a 12V input. Some electronic devices are set up for a 5V input signal, so 12V could fry its brains. Perhaps that's the reason some tachos use a trigger wire taped alongside a spark plug HT lead to induce a low voltage signal.

Incidentally, the same applies to the tacho output pin on the ignitech box. It has a switched 12V signal, so the tacho needs to be happy with a 12V input. I guess most would be because they're designed for automotive use, but it might pay to check the specs if the info is available.
 
Makes perfect sense (points signal, square wave), Cam.

Pretty sure the ZXR is just wired into the 12V system, but I'll check the wiring diagram. Where or how would a 5V power source be generated on a 12V moto?
 
Come to think of it, I've never seen a tacho with a 5V input. I only mentioned it because 5V is a common signal voltage for a lot of electronic devices.

I suspect that if tachos needing a 5V input existed, they'd be limited to those that are wired into a printed circuit type dashboard like you'd find in a car. Stand-alone tachos would be pretty useless if they couldn't handle 12V. I've seen some that specify an input signal of between 0.5 and 30V. So I probably shouldn't have chucked that particular red herring into the pond.

However, in the very unlikely event that your tacho is wired for a 5V input, you could use a simple voltage divider circuit.
somanytech.com

12v to 5v Converter- 4 Simple Circuits for projects - SM Tech

All 12v to 5v converter circuits using different methods, with its working and formulas, 12v to 5v dc converter - voltage regulators for various projects.
somanytech.com somanytech.com
 
The last time I used an electronic tacho (on one of my 500/600 twin race bikes) the signal wire was wound a few times around one of the HT leads. But I suppose that’s doesn’t mean they all work like that.
Whatever, I’m interested in the outcome Rob as that would be an option for replacing the useless tacho on my track bike.
 
5 v Tachos are f.e. on the Zane bikes. They get their signal from the ECU instead the coil. That's why I said make sure the model the tacho comes from is carbs equiped =>no ecu ;-)

The Ignitech can work with both tachos me thinks and even with spark every crank turn or every second. If you have an ignitech, you can use the tacho anyway as you have both options, 5,7v or 12 v
 
Instructions here:
www.z-power.co.uk

Tacho Electronic- Z-series

This is a replacement tacho for the 900/1000 models. will also fit the Z650 models. Looks like an early Z1 clock with the stop lamp red light in it but is in fact an electronic unit. when you switch the ignition on the needles flick round like a modern bike. Easy to wire in, just having three...
www.z-power.co.uk www.z-power.co.uk

Says the tacho "needs a feed" from the points-to-coil wire. This is the low voltage side so I am wondering if it is DC connected as opposed to a wrap around inductance pulse sense.
 
I just came across your thread Rob.
For what its's worth, I fitted an after-market tach possibly similar to yours. I run it from the Ignitech Tach 12V DC square wave output.
My tach instrument input requires +6/-6v (nominal) input, effectively ac.
So I use a capacitor in series between the Ignitech 12v DC sq.w. and the tach, and also a diode to ground on the tach side of that capacitor. This gives me +0.6v to -6v input to the tach which works. I can send you a sketch if you think that might work for you.
Chuck
 
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Hi Chuck,

The tacho appears to connect to a coil primary, so I would assume it has an internal isolating capacitor, resistor and clamp diodes to protect the electronics from the few hundred volts flyback on condensor/points.

I am thinking of using a further two capacitors and diodes, one for each coil primary as an "OR" gate to get the correct pulse frequency for a twin.

Probably 1KV rated diodes and capacitors.

Cheers,
Rob
 
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