Briggs & Stratton 550 EX 2013 Lawnmower: Trying to replace broken pull cord. We have the new one in place, however, it is not recoiling. We would like a diagram (operator's manual not detailed enough). Having difficulty, also, finding the model # as requested xxxxxx-xxxx-xx All help, so we can get our lawn mowed, is greatly appreciated. xxxxxx-xxxx-xx