Elliot electronic tach

htown16 · Jul 6, 2016

Anyone have any experience installing an Elliot electronic tach. I picked up one off ebay. It came off a Commando with a Boyer ignition. The seller was unclear on how the wiring was hooked up and didn't have the instructions. On the back of the tach it say red 12v+, black 0v-, green tach and cyl 1:1 . I'm actually going to install it on a 70 BSA Thunderbolt, Pazon surefire, 2 six volt coils wired in series, and positive ground electrics.
Any help would be appreciated.

grandpaul · Jul 6, 2016

1:1 may rear double the RPM with a wasted spark system (unless it's programmable)

htown16 · Jul 6, 2016

Old Brits carried them at one time says that the 1:1 is used on electronic ignition and the 2:1 with points. The seller had it on a Commando with a Boyer. The Boyer and Pazon Surefire are both "wasted spark".
Here was Old Brits ad.
http://www.oldbritts.com/15_100006.html

grandpaul · Jul 7, 2016

Well, there you go!

htown16 · Jul 7, 2016

My question is how to wire it. No instructions came with it.

maylar · Jul 7, 2016

htown16 said:
My question is how to wire it. No instructions came with it.

well... you said

On the back of the tach it say red 12v+, black 0v-, green tach

So, Red is ground (positive), black is battery negative (from the ignition switch, or from your kill switch if you have one), and the green will go to the Boyer's output lead to the coils (or the + terminal at one of the coils).

htown16 · Jul 8, 2016

Here's the info on the back.

I understand how you would wire it on a "normal" negative ground system. Red would go to a switched lead from battery positive and black would go to battery negative and ground. Green would go to the coil terminal receiving switched signal which I think on a negative ground system would be the + coil terminal.
Question I'm still can't get my head around is do things need to reversed on a positive ground system.
Now about anyone that has installed the Pucca Smiths or Legendary Motorcycles electronic tach?

ILLF8ED · Jul 10, 2016

htown16 said:
Here's the info on the back.

I understand how you would wire it on a "normal" negative ground system. Red would go to a switched lead from battery positive and black would go to battery negative and ground. Green would go to the coil terminal receiving switched signal which I think on a negative ground system would be the + coil terminal.
Question I'm still can't get my head around is do things need to reversed on a positive ground system.
Now about anyone that has installed the Pucca Smiths or Legendary Motorcycles electronic tach?

Positive is positive, negative is negative. Don't get confused just because positive Is common ground. Black lead from th tach connect to brown/blue negative lead from the battery which is the switched lead. Red from the tach concert to red ground.

utahnorton · Jul 10, 2016

I have the installation instructions and wiring schematic for the new Smiths electronic gauges on my website that shows how to wire them for both negative and positive ground. How that would relate to the Elliot tach I haven't a clue as I have never seen one before but at least you can see the relationship in wiring the Smiths both ways if that helps. Obviously yours will be completely different. I will be at the Norton Rally in Quincy, California on Tuesday and will have a display if you want to stop by and take a look. Also Matt from CNW will be delivering a bike there with my gauges on it as well.

Cheers,

Tom Kullen
http://www.smithsgaugesusa.com

L.A.B. · Jul 10, 2016

illf8ed said:
Black lead from th tach connect to brown/blue negative lead from the battery which is the switched lead.

Brown/blue is permanently 'live/hot'. 'Switched' negative is white ('70 BSA or Commando '71-on).

htown16 · Jul 10, 2016

Thanks for the info. I'll run the black to the white wire coming off the ignition switch and the red to a dedicated ground back to battery positive.
I'm assuming the tach lead goes to the negative post on the first coil in the series as that it the signal coming from the ei box? That would be the Black wire from the Pazon box.

Elliot electronic tach

htown16

grandpaul

htown16

grandpaul

htown16

maylar

htown16

ILLF8ED

utahnorton

L.A.B.

Moderator

htown16

Similar threads