26 hp B&S has 500 hours on it, and runs great. A few times lately however, it has kind of a muffled sound, and decrease in power. It did that yesterday a couple of times, and then, just ran great, and normal, the rest of the day. Does this sound like it was a little obstruction of fuel flow through carb or what. Otherwise, it is just as good as new - uses no oil, and starts easy with the automatic choke.