2006 txt pds stretch 36 to 48v conversion

[christian1016]

i have recently upgraded my 2006 ezgo txt pds cart to 48 volt lithium along with navitas 600amp controller ,heavy duty 48v solenoid ,new 2ga wires, and plum quick 'zombie motor' (as recomended by plum quick).i now have two issues i hope to get cleard up.one being the cart runs but at speed for lack of better words is 'bouncy' second is then need to constantly switching the key switch on and off during operation to keep the cart moving example stopping ant a stop sign pressing peddle and npt moving reset key and your off till you stop again.what am i missing?i hope there is enough imformation for someone that knows more than i