bouncing tach

[Kal k]

I have a 79 invader and it has a bad bouncing tach and tryed a tach off a 340 invader on it and it dos the same thing. Any ideas?

[sxrsist]

i have tried a few tachs. never get smooth reading either.

[gixxer6]

I had an Invader with a bouncy tach, I replaced it with a NOS tach and the problem went away.  It seems like when they get worn they bounce. 

[rminier]

http://kawasakitrax.com/kawiforum/index.php?topic=1657.msg10735#msg10735

I haven't tried what "sprocket" suggested on this, but I intend to. I bet it works.
I wonder if there is a cheap resistor inside the tachs that wears out after 40 years?

[Kal k]

Ok thanks for the help

[sxrsist]

i had a tach the never bounced on my invesder and swapped with ltd and still bounced on ltd and ltd one never bounced on invader. its in sled i think

[jimvw57]

The tachometer is simply a voltage meter that reads the voltage from the engine. as it runs faster, it makes more voltage. Since the voltage made is AC, there is a regulator that converts it to DC and they use that for making spark and lights. I wouldn't worry about a bouncing tach too much as it isn't even that accurate anyhow.

[gixxer6]

The tachometer is simply a voltage meter that reads the voltage from the engine. as it runs faster, it makes more voltage. Since the voltage made is AC, there is a regulator that converts it to DC and they use that for making spark and lights. I wouldn't worry about a bouncing tach too much as it isn't even that accurate anyhow.

These tachs are pulse counters, not volt meters.  The faster the motor spins, the higher the frequency of the pulses.  They should be quite accurate. 

[Kal k]

I ended up putting a after market tack on my invader and it fixed the problem. Thanks for the help

[Interceptor398]

There should be plenty of used tach's out there?