FWIW IMO
It looks like a car tacho, attach to handle bars ???
Wiring diagram/info for the tacho??
It gonna take a braver man than I to start delving into the engine management system / efi to attach it.
Good luck
A forum community dedicated to Harley Davidson Street owners and enthusiasts. Come join the discussion about performance, classifieds, modifications, troubleshooting, maintenance, and more for the 750 and 500 models!