The main shaft on the original engine is 3/4" x 2-5/16". The PTO shaft is 5/8" x 1". This engine has been discontinued and there is nothing else that will directly replace it. You may be able to us a 6hp Briggs Intek OHV engine. However, the height of the PTO shaft is shorter and you would have to change your PTO belt or raise the engine up and use the same PTO belt and get a longer main belt for it. You would also have to change your PTO pulley to make this work.
