I have a 84 ironhead sportster and it is a bobber I have a s&amp\\;s carb I cannot find the evos switch on the bike do I need one ? Thanks Charly

 

That switch if you have one is usually mounted by the carb. One wire runs from the switch to the ignition module and it grounds itself on the block. If you're running an S&amp\\;S carb you won't need that switch on there.

 

Do you mean VOES?

 

That's the right abbreviation for it pococj, but I knew what he meant in his question.
Stands for: vacum operated electrical switch. Thanks for pointing that out.