Thanks Mike, it will be interesting to learn what you find. My first guess would be that the valve won't be able to open as far as it should, for some mechanical reason. If the engine has ever been overhauled, it could easily be due to misassembly in the valve retainer area (such as someone trying to fit a valve stem seal the engine isn't supposed to have), but if it hasn't been overhauled, I doubt any serious assembly errors would have happened in a Honda plant. I think part of the problem, though, is those rockers seem to be very easy to break. By the way, if you've broken a few, are you sure you didn't ever have a loose broken off piece drop into the oil pan? If you did, it is likely to get caught up in the moving parts sooner or later, and cause a worse problem than you already have.
