Smiths Original Style Tachometer, 6000RPM, 80mm, Brown - All Questions

Thanks for the enquiry. We contacted our supplier and one of their engineers replied with the following:

"It's a bit of a difficult one to answer as a lot of the high output distributors tend to break electronic tacho’s of all makes, usually they with work up to about 4000 rpm then the tacho input gets swamped by the boosted signal and the pointer drops to zero.
As you are in the U.S it adds an extra dimension. We have changed our input circuit on quite a few tacho’s for this problem but in the last few years there have been a handful we couldn’t get to work reliably.
A good start is to ensure they use suppressed spark plug caps but can’t give a guarantee it will work."