Gilera DNA is derestricted but still only does 32 MPH?

Reference previous question about derestricting DNA 50. The bike has no spacer between the variator cones and has an aftermarket exhaust with no restriction in. It gets full throttle at the carb and a brass disc which was fitted to the mouth of the carb has been removed. The bike still only does 32 MPH on the flat at 6500PRM. Drops to about 25 MPH uphill. Downhill it will rev to 11,000 at about 50 MPH. On the stand just spinning the back wheel it will rev cleanly up to about 12,000. Could it be electronically restricted also?, but if it had a rev limiter it wouldn't pull 12,000 RPM on the stand??