Small Engine Troubleshooting Problems? Ask a Mechanic Now.
From the indicators , you are having a charge pump failure in the hydrostat. The bogging of the pto tells me the pto brake is coming on, it requires the pressure from the charging pump to keep the pto clutch turning. And now with the hydrostat on the right side slipping, Ii think you are in need of a pump! And the complete system cleaned! Sorry.
Charge pump is on the back of the transmission housing, see picture,
Did you find problem?