Speed sensor what is it for?
Noticed Speed Sensor diagnostics under (EFI section!) in the Service Manual for mk3.
What function would it serve for the EFI (apart for obvious speedo/odometer functions)?
Could it be that the speed sensor compensates for increased air resistance when the motorcycle is cruising on the highway for example?
If so, perhaps changing the final drive gear ratio (by changing sprockets) could be also affecting the air/fuel ratio in the wrong way?