Topic: cb 550 tacho

[Kevnz]

Hi All,
In addition to my indicator woes, the tacho (s) on my new 550 don't work. One is the original, the other a lookalike . The lookalike would read about 1k at idle, but not respond to revs. I put the original on, but it doesn't even register. I pulled the lookalike apart and cleaned all the bearing surfaces. The movement is free and does not bind. The magnet rotates, so the drive mechanism is ok, but virtually no movement of the needle. I have an old cb350 tach that works fine (but obviously does not fit) so the issue is definitely with the instruments themselves. The mechanism seems so simple, I can't see what could possibly be wrong. Does the magnet lose its strength,
and if so, is there a cure?
Thanks,
Kevin

[RickThomas]

There is a tension spring on the shaft of the tachometer that runs vertically. On one end is the bell and the other is the needle. Check to make sure the tension spring is working by gently turning the tach needle up to 6k and see if it smoothly comes back down to 0k. This motion should be driven by the tensioner, if it is broken, your tach will not work.