I have a utility mower powered by a B&S motor that is just amazing. It is a 4 HP 2 stroke that just goes and goes and starts every time, even when it is 'sick'. It is onto its 2nd body (or 3rd body - it was very second hand when I purchased it in 1990) and is not something I will part with but I have never been able to find another one. Motor numbers read: 096722-0205-01-870223. The B&S site finally yielded a manual etc when I substituted 0205-01 with 0205-99. It is a series 96700 motor.
I have a few B&S 4 stroke motors and a few bodies I could swap or will look at buying if anyone can point me in the right direction. Like I said I have never seen another motor like this one and I have scrounged a lot of tips and trawled a lot of web sites over the years.
cheers
G