Repeat Oil leak on older B&S 17HP single
 

My brother has gotten fed up with his ~20 year old Scott's/John Deere S1742 riding mower, and is gifting it to me. He said the engine keeps leaking oil even though he has had it "fixed" multiple times. I have yet to see the tractor in person, only a picture.

I'm sure this 17HP B&S engine is used in other tractors or even Cub Cadets. Is there a common point of failure where oil would be leaking? Why would it continue to leak after multiple repairs and how easy would it be to fix?

Even if I can't fix it, I'm sure I can repower it with another engine or even just use it for parts (the tires are in good shape from the pics).

You need to be more specific/see it before jumping the gun.

I'm not even going to speculate at this point :D

Ok I got more info. It's leaking around the valve cover. My stepdad has "fixed" it for my brother multiple times and it keeps leaking. I don't know all the details or specifics of what he did/tried.

What could cause the valve cover to leak repeatedly?

Improper repair is the first thing that pops into my mind.

Finally got the tractor to my house. Put some 20W50 oil in the engine since it was all I had. It fired right up and I can't see any leaks or smell burned oil. If there is a leak the thicker oil can't penetrate it. Oh well this will be a good backup mower, can't complaint about the price!