JohnnyT,
Well I did a little experiment with my lawn-mower. It holds 24 ounces of gas, to keep the ratios right, just a fume of bleach would be needed to match the ratio of bleach to fuel. I instead, added once of bleach to the tank, and filled it. Started the mower and started to mow. It stalled, of course, the bleach did not mix with the gas, and went right to the carb. Left it overnight, added 5 ounces of rubbing alcohol and tried to started it, I got tired of pulling the rope and used the starter, after a few seconds of cranking it sputtered to life, and then ran fine. I pulled the carb bowl to check for any damage, and found none. It was very clean, which I expected since I ran alcohol through it. I know, this is not an injected engine, or diesel, but to duplicate the same circumstances, would be very hard and time consuming, not that what I did was not time consuming. Considering the very high-end B&S engine and high class carb, I really do not thing there is anything to worry about.