1982 Spectre Tacho Fault

Hello KZr Forum Members,
I'm new here, but after searching the forum I don't think this precise query has come up before - I'm hoping someone out there has the knowledge I need...
I've very recently bought a 1982 KZ1100 Spectre which is mostly in decent running order apart from the tacho doesn't work.
The tacho on this one gets an electrical feed from the battery and then uses the ignition coils to get the rpm signal.  I've checked the voltages to the tacho and they're fine, so it seems like the fault is with the tacho itself.
Does anyone know if these are repairable, or if there is anyone in the UK who repairs this type of tacho?
Thanks in advance...

Welcome to the forum Sparfla!

Mine failed similarly...
The mechanism comprises a semicircular magnet, and (very) tiny moving coil...





One wire on that tiny coil "fatigued" and broke off the connecting pin, which is soldered to the tiny brass spiral return spring.

I had to unwind the coil to get to the end that broke off, then rewind it, leaving a "tail" that I could solder back onto the pin.
The coil measures 77ohm when properly connected.

So, I managed to repair it myself,  but it was quite "fiddley", being so tiny.

H.
 

Thank you so much howardhb - that is so useful, great to have the photos too.  Looks as though I might be testing out my soldering skills at the weekend!

Cheers

Welcome to KZRider 
Lots of great help here. 
Dave

Hi H,
I've only just today found time to remove the tacho to see if I have the same fault as you had. I have the tacho off the bike but it doesn't seem to want to come apart and I don't want to force anything.  Can you recall how the unit is held together?
Thanks again,
Sparfla

Okay, I've opened the case, next "how do I" is about getting the gauge pointer separated from the mechanism behind the dial?

You can use a couple of spoons, one directly across from the other. The tips of the spoons should be under the needle, just touching the shaft. Pry very gently on each spoon hanndle.

Seems like there is an article on this under the Articles tab.

Welp, memory fail. I do not see the article here, but I do have a copy. 

Two spoon, who'd have thought...it worked a treat!
Thanks TexasKZ - I love this forum 

Sparfla wrote:

Two spoon, who'd have thought...it worked a treat!
Thanks TexasKZ - I love this forum 

And the money you saved can go toward a set of carbon fiber wheels, or that platinum plated titanium widget installer you have your eyes on