the stock tach can be repaired alright - you are talking about the older very big version? - but it is not worth the bother, 'cause it will just break again. And again. And...
After the third guaranty-replacement tach, I gave up.
There are several possible replacements. The most "original-looking" is to mount the complete instrument unit from an SZR. You do need the CDI from the SZR as well for the tach to work which is no problem.The speedo hooks directly. It would all depends on whether you can garner something like this off eBay cheaply (+25€ for the isntrument, 50-80 for the CDI, but you can sell your CDI in return), otherwise it would be just as expensive or more, than just ordering the new model instruments new. In that case, almost any of the aftermarket electronic devices would be cheaper to much cheaper.
Very good and not expensive as such things go is the Scitsu from merry old England. I would recommend this first and would have gotten one myself, had I know about them back then:
http://www.scitsu.co.uk/docs/main.htmyou would need model B1 for an engine with wasted spark. Normally, the range to 8000 is sufficient unless you are contemplating some engine tuning. Then you should go for the 10000rpm range. £121 to Aus. is cheap if you ask me. a new original part costs more and is nowhere near as good. These things have a very good reputation.
Then there is the Stack, also English:
http://www.stackltd.com/st700.htmlThese are
EXPENSIVE, but they also have an extremely good reputation and as you will see are complete street instruments with digital speedo, control lights and all the rest. very sexy...
Here are a few links for other combi instruments:
http://www.acewell.de/Digitaltacho___Drehzahlmesser.14.0.htmlhttp://www.motogadget.de/en/frameset.htmlI use this one and have used it since about 1996 when I got fed up with the stock unit:
http://www.det-motorrad.de/shop4/start.htm?d_100_DET_100_Cockpit217.htmsorry, the site is only in German
It is small,light, waterproof, dependable and repairable for small fees if and when (crash) it might be necessary.
"Kompaktes digitales Cockpit mit gleichzeitiger Anzeige von Geschwindigkeit und Drehzahl, Tages- und Gesamtkilometerzähler,
Bordspannung, Öl- oder Wassertemperatur. Das Cockpit ermöglicht die Speicherung von Maximalwerten, Kontroll-LED's für Neutral, Fernlicht, Blinker, maximale Öltemperatur (programmierbar) und Öldruck. Mit TÜV-Gutachten!"
Translation: "compact digital cockpit simultaneously displaying speed and RPM; odometer and trip odo; voltage output; oil or water temperature if a sensor is installed; maximum values can be stored; control LEDs for neutral, highbeam, blinker, maximum oil tempperature, and oil pressure. Official vehicle inspection documents."
Then there is always the possibility of using the mechanical tach from a SRX or SR - both work. The angle drive goes on the right side of the cylinder head where that small round sheetmetal cover is. As long as my racer was running with a magneto, it had a SRX tach:
THe SRX is basically the same engine, so this is perhaps the most straight-forward, made-for-the-engine possibility after all. I could sell you this setup complete with angle drive as shown if you are interested; you would need to make some sort of plate(black plastic or alu) to mount it in the hole in the panel. It is smaller than the MZ original so that would not be a problem, really.
Posted: Tue Nov 13, 2007 6:36 pm