After hassles with my first tacho being slow and trying to fix it..result tacho in million pieces. I ordered a pretty good looking one off Ebay from the UK. This one now doesn`t rev past 6500rpm..otherwise working fine. What do I have to do to get one that works?

I have said this before I think, seeing as Yamaha are so unbelievably lazy with some of there kit I would bet real money that a comparable taco of the same year will have the same guts in it. Be it Dt175, RD125 even a XS if your pushed .

I know you had a dt one you were using have you torn it down to have a look? Or did that come off your dt as a temp fix?

It will be either the magnets losing strength or the spring losing flexibility that make it read lazy.

Hi Cynic..yep now that Ive opened and learnt little bit bout these tachos I would suspect spring at the back has lost tension..although I`m told this side the magnets could be likely culprits as well. Yes had a DT175 temporary tacho on there which revved happily to 8000plus. Downside I had no temp gauge on there (at least that works on this tacho).

Is it possible to swap the guts of the/a 175 taco into the lc housing. Swapping the faces.

Should be..although cable angle is pretty way out. Wouldn't like to try it myself..soon as you remove the needle to change faces, spring behind it loses all its tension.