Poula Pro Mower

Hi,your machine is probably a hydro static drive & needs the oil changed in the transmission.
But the pump that pushes the oil around inside it is probably to far gone for repair.
I am not sure about this machine but we have had a simlar problem with a rideon this summer.
It has one pedal that you push forward for forward movement & rearwards to go backwards.
We were able to get a new drive pump for the transmission but it was expensive, most of these machines have nearly the same transmissions so getting the parts should be no problem.
Also we do know is that there are some machines with oil emersed discs inside (like wet type clutches) these also need regular oil changes & can burn out without oil. (Bronze plated disc)
You would need to find the name plate on the transmission & there should also be model & serial no on the casing.
Once you have these details you should be able to find transmission parts lists online.