i took it off , but just wondering what it was?

 

That's the mount and sensor for a bike computer...

 

what does it keep track of

 

It is a replacement for the speedo...

 

cool thanks for the info.... u think the orginal owner disconnected the orginal speedo so the bike won't register any miles?

 

If the pink/green wire is disconnected the bike will run normally but not indicate any speed/mileage. Check that wire to see if it's been modified/cut/spliced and that should answer your question.

A lot of guys installed the bike computers because you can indicate a more accurate speed based off the tire circumference. The stock speedo reads about 7% high. I would read higher or lower if the PO modified the gearing.