I was riding the other day..kinda just cruising along at about 50-60..All of the sudden I hear a hissing sound seeming to com e from the left side of the engine and then the speedo drops momentarily to zero, then back to 50..lasts maybe 1-2 seconds at most. Did this about 2 times then runs fine. Has not done it since. The sound was almost like fuel injection sound when you turn the switch on initially, but maybe louder since I heard it at speed. Tank was full so it was not the FI trying to suck in gas...anyone ever had something like this happen? Does it sound serious? It has been about 100 miles since and has not happened again..