When we bought our house last year, a worn out sun faded Polaris 360 (pressure side cleaner) came with it. At the time, the 360 only had two wheel drive (broken belt), but otherwise operated normal. An hour or two would clean up the bottom of the pool nicely. Over the winter, the 360 lived in the water, and over this past winter, it became one wheel drive after the second belt popped.
A few weeks ago, I bought the rebuild kit for it and made it look like brand new. It came with a new backup valve, but I did not put that in as the old one seems to be working fine (no leaks of cracks). When I put it in the pool, I did the wheel RPM test and it was over 40 RPM. I changed out the white pressure relief valve at the wall fitting with the blue one, and now the RPM is at 32. Everything seems normal, except that it wants to ride the perimeter of the pool, instead of turning and cleaning the center.
My pool has no deep end, and has a nice curved transition from wall to floor. I have tried various settings on the thrust jet with no apparent effect, it does not want to turn. It mostly will track straight and follow the curves along the perimeter. The back up valve cycles every 3 minutes or so.
It appeared to work much better before the rebuild. Any ideas what I should try next?