i bought a turbo turtle used from a neighbor(they just moved and had a pool for 1 summer at old house)

for the first week it worked great, but since then it only seems to want to go one way. the rear jets on the turtle only go 1 at a time and when it switches to the front jets both go causing it to go to one end of the pool rather quickly.

not sure what the deal is but any help is much appreciated.