I've been running these engines for decades, but I've never seen this. I've got a new Kaw FC420V on a mower. This engine was purchased in the mid 90s and has been sitting in a box until this spring when I mounted it on a WB. So it's been running now for about six weeks. During those six weeks, the muffler has become flooded with oil 3x. It's not because the crankcase was over filled. It's not from parking or resting the mower on a slope or tilting the mower. It's not from stopping for a long or short period of time. It seems completely random. Each time this happens, there is so much oil in the muffler, it's takes 2 (instead of 1) pulls to start, and then it blows tons of smoke for a good three minutes. I've seen one minute on other Kaw engines over the years from tilting or what-not, but three minutes seems excessive. To me, it's as if the engine fly wheel stops at a certain point, and the valves stop at such a position that oil somehow leaks into the muffler. Yet I've never seen anything quite like this before -- with this much volume. Can anybody comment on what might be causing this? Thanks!