81 GS850 - converting manual tach to electrical

[jables617]

Hi Folks -

Quick question - I know that if i want to replace the mechanical tach on the bike with an electrical one, i have to wire it into the ignition - but the project bike I got came with an electrical tach that's not hooked up and has no documentation. Do I need to chase that down to find out what the proper configuration is, or can I safely wire it to the ignition with 1 spark/1 revolution.

[eil]

If memory serves, the later model 750E's had an electronic tach that tapped the primary side of one of the ignition coil. I swapped the mechanical tach in my '81 750E for an electronic tach from an '83 (I think?) but it was very fiddly and only worked because the '81 had a truly cavernous square-design instrument cluster.

We don't know which electrical tach you have, so it's hard to give any useful advice.

[Who Dat?]

Charles is right, we can all guess all day long, but none of the guesses will mean anything unless/until we know what you have.

That said, what you need to do is find out what you have. Then share that with us.