How to test a tachometer

[tmt]

I think my tach is reading low. How can I check it to be true?

 

[joey nathan]

Re: How to test a tachometer

You almost have to sub in another, brand new one, to be sure. A dealer would have a trusted tachometer they could use to verify accuracy...

 

[eavega]

Re: How to test a tachometer

I picked up an optical tach for under $25 on amazon. I wanted something that would verify engine speed rather than just reading pulses.

Otherwise, some of the higher-end timing lights have a tach built in. Either way, I would think the best test would be to hook up a second tach and see if they read the same.

-E