A friend has a steiner S-20 that has a bad Onan engine. He would like to repower it, but the cost seems to be a holdup. Is it possible to rebuild the Onan, or should he buy another engine? Which engine would work the best with the least amount of fabrication? Also, I know of another steiner that isn't being used much at all. It is the 525, has a 6 foot mower, 6 foot blade, and a factory cab. What would it be worth to buy?