I'm aware of the fact that Tecumseh and Briggs and Stratton both use plastic timing parts in their OHV engines. I'm not too crazy about plastic parts in engines. Should I be concerned about both companies' OHV engines because of this? Are the Tecumseh L-Head engines a good design? All metal parts? How about the stories I hear about L-Heads blowing rods (or is this just a matter of keeping your oil full and clean?) Should I trust the L-Head more than any OHV engine? I kind of get this impression from a couple of small engine mechanics I've talked with. Are larger engines a potential mechanical problem? I'm thinking of engines larger than 10 or 11 horsepower. A small engine mechanic told me that such a larger engine could invite more potential problems, but I can't exactly remember what he said without misquoting him.I'll probably be back again with more questions. In the meantime, thanks for any help on these latest ones.