Page 1 of 1
Id'ing Smiths tacho
Posted: Wed Dec 03, 2025 8:57 am
by bendik
Hello
Fot those more familiar w these than me, does the 4-1 marking on the face identify the Smiths tacho as a 4/1 ratio rev cpunter that wouild be suitable for use w a cam drive?
Re: Id'ing Smiths tacho
Posted: Wed Dec 03, 2025 10:17 am
by Roland
I have this one working on scrambler 350
Re: Id'ing Smiths tacho
Posted: Wed Dec 03, 2025 10:18 am
by DBDBrian
Yes I run a Smiths 4/1 rev-counter off the camshaft. The drive off the camshaft will need to be 2/1, and the correct output rotation for your instrument. If you have a 2/1 Smiths drive it can be assembled to give clock or anti clock output. If not the instrument can be converted to except clock or anti clock input. If it's a chronometric unit.
Re: Id'ing Smiths tacho
Posted: Wed Dec 03, 2025 12:37 pm
by LaceyDucati
That is the correct 1:4 rev counter for a Ducati cam drive box. That is generally a good type of tacho.
Nigel
Re: Id'ing Smiths tacho
Posted: Wed Dec 03, 2025 1:01 pm
by bendik
Thats good to hear Nigel. Only thing that being going my way on this build

The covers I bought scrubbed up good.
Re: Id'ing Smiths tacho
Posted: Wed Dec 03, 2025 5:00 pm
by blethermaskite
I have been running a smiths race rev counter on my mk3 350 for nearly 50 years since the original spec. one disintegrated before I even had the bike run in! In my experience these instruments work just about perfectly and are accurate. When I was rebuilding my 250 desmo some years ago I fitted one to it as well.........wouldn't use anything else.
Cheers George