Scag SWZ52A-18KH Mower, Commercial Walk Behind

This recoil start engine has a 1" x 3-5/32" shaft. You could use the electric start engine listed here and use the recoil starter of the old engine. If you wanted to utilize the electric start, you would have to hook up a battery and change the key switch to one for electric start if it is just set up as a shut off switch.