Posted 2 weeks ago
I once had a tachometer with a faulty also, a local guy repaired it with an external cb which was ugly even hidden under the dash. Eventually I found a NOS cb and proceeded to swap it over. It didn't work. So I sourced more tachos that worked to use as parts since mine had a perfect face. Nearly completed the swap and dropped it, bending all the needle and balance counterweight wire which I could never correct. I ended up buying the OER tacho at about 500 shipped and lost several working tachs plus nos CB, all with international shipping. I can't answer your question but it can get very expensive chasing parts for a tach repair, look for a replacement if possible.