Need to read-up on the CVT systems these have. No gears, just clutches & belt to transmissions that have forward ranges as in High and Low. Many have had problems with the plastic parts of the flyweights...that's a parts of the Drive or Primary clutch, melting under the extreme heat they can generate. This stops them from moving thus stops shift-out. Time to pull it apart for a complete inspection. Grab your service manual and do both while in there.