So I know its not so MMM approved but I have multiple properties and a few lots behind my home.
My dad gave me a push mower he was going to throw away. And my neighbor gave me a mower that no longer ran.
One had a great base and the other the mower worked. Both are B & S motors. The one not working I tried to get running but to no avail so I started to take it apart only to find the manifold had cracked. Yea no wonder. So I took the motor off and replaced it with the working motor and wala.
I then took the bad base and fixed it up enough that my 2 year old will be able to push it around the yard. He likes to now. No worries no motor or blade. Its just the deck with a shortened handle. Next season I will need to replace the blade or sharpen it.