made oct 24, 1989. its 19ci, so it could be 8, 9, or 10hp but by the owners manual i think it is 8hp.
Heres your manuals.
http://www.briggsandstratton.com/ma...e/docsearch.aspx?enginelookfor=195432-0720-01
And also, dont start it up without an exhaust of some sorts.
And could you get a better picture of the crankshaft? it almost looks like its tapered.