I ran across a post from about a year ago about an oil leak from a briggs engine and it sounds a bit like the problem I have. I have a Craftsman 54" lawn tractor with a Briggs V-twin 24HP (Model #445677-0413-E1). While mowing through some heavy grass my mower lost power all of a sudden and began to smoke. I shut it down immediately and checked under the hood. There was a significant amount of oil leaking from somewhere above the oil drain plug. The leak seemed to stop when I shut down the engine and started again when I turned it over. Curiously there does not seem to be significant oil loss, as indicated by the dipstick. I have the Briggs repair manual for my engine. I should also note that when I turn the motor over by hand I can hear a sucking sound somewhere down by the dipstick tube. I also noticed an oily residue in the carb intake. Does this sound like a problem with the crank case breather, a leaking o-ring on the dipstick tube, or a blown sump gasket? Or do I just have to start with the simplest repair and work my way down to pulling the motor entirely? Any help you can provide would be great.