Okay, on my way to work in the morning.. look down, the seedo reads 0.. it was like that about half way to work, then as I would slow up the mph numbers would jump around, untill finally it worked smoothly. also, the miles were not counting up when the mph wasn't reading. I leave from work, same thing happens, but now the red "F1" light was lit. But as I got closer to work the mph speedo started to work but the light was still on.. The bike runs well, sounds good, I don't know whats going on???
please help.

 

Speed sensor is probably shot.

 

cool now when you sell it it'll have less milage

 

Check the sensor that is attached to the counter shaft sprocket cover. could be coming loose or bad!

 

hahaha thats what i was thinking