Electronic ignition and the electric tacho

[Cerberus73]

Reading up the literature that came with the electronic ignition kit that i bought a month or so back. it states that the tacho fitted to the ETZ 250 will not work with their kit (powedynamo.. without the new rotor) so was wondering if anyone has came up with a solution to keep the original instrument fitted and operational, as from what i can work out powerdynamo say that you can fits an alternative tacho etc.. but i want to keep my bike as cosmetically original as i can. i am guessing the original tacho takes a reading from the coil, and since this is replaced with the new kit, thats why it won't work.

Any ideas or solutions?

[Agronski]

Don't know enough about either the ETZ or the PowerDynamo systems (still running 6V and points on my TS) - but I thought even the later ETZ's had a mechanical tacho drive?

If there really is an electronic input rather than a drive-shaft, you could try putting an oscilloscope on an unmodified ETZ and check the format of the signal - it might just be a single pulse in time with the ignition. If so, you should be able to borrow one of the pickup signals from the ignition unit. It might need an amplifier or similar to drive the tacho, but I doubt the circuit would be very hard.
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[dwc]

Hi,
Just revisiting the site after a while.
Do you have any photos of your fitting of the powerdtnamo system. I have the same but have hit a snag, in that I have three wires blue, red/green and black that I cant find homes for.
Any help would be appreciated.

Regards DWC

[vicar]

I resorted to fitting earlier mechanical rev counter and speedometer the parts were cheap and it works .The picture shows the instalation before sorting the cosmetics,

[davegsm82]

The answer is YES! It can be done!

You have to disassemble the square Electronic 'CEV' Rev-counter and turn the calibration potentiometer inside, I did it to my 301 when I fitted the VAPE system to replace the original MZ regulator/rectifier/ignition unit.

As far as I remember there is only one 'pot' to turn inside, the trick is getting an external 'tacho' and steady idle where you can calibrate what you see on the electronic dial against what you have on the external one.

If you have the round mechanical type, then it works regardless of what type of electrics you have fitted since it's a mechanical drive.

Dave.