I think the Vanguard is a great engine, and I'm not suprised you haven't had any real trouble from yours. BTW, all the Kohler's I've had with OH valves had sooty/seepage covered valve covers too. Not quite as bad with my Kawi's for some reason. These days I'd take a Vanguard as readily as I would a Kawi, and that's saying something for me because I've had extremely good luck so far with Kawi's. Not so much with Kohler anymore.