Statesman Lawn Tractor

Hello all, so I have an older/old statesman lawn tractor that was given to me. I got it running, the problem I have is that it only has 1 speed. It is a hydro, with selector next to seat. But no matter what setting its on, it's one speed. Not sure if its worth messing with. Any ideas?

Time to check the condition of the belt and the idler tension pulley and arm. If the belt is worn or the idler pulley and/or arm is not moving freely, the condition you posted would result.