can someone clue me in on this mower. I just got it it has set for a few yrs motor runs good the problem is one of the drive wheels was not moving I back off the brake lever it will roll now. but with engine running it just creeps along slow push pedal further down kills the engine both forward an reverse.brake pedals and parking brake do not move seems frozen up what controls the hydro pedals to kill engine when engaged im lost on it.