My Polaris 300 4 wheeler will not move when put it in gear and when it trun off and turn to push it to get out of road the back wheel will not turn..

There are a couple things that you should check with these pool cleaners if the wheels are functioning properly. Check the filter screen in the in-line filter assembly and clean if necessary.Make sure that you do not have any debris or obstructions that could be halting wheel function. Even though you seem to have plenty of water, check the RPM and make sure they are between 28 and 32.