Family member brought me his Briggs 7.25 on a 5 year old Troybilt walk behind. I hadn't seen it nor serviced in a year. Turned it on it's side to drain the old oil; nothing came out. Dipstick showed nothing either. He had somehow failed to check the oil during the last year and also let the air filter get completely clogged. I feel certain that he mowed with it many times in this condition or when the level was quite low. So I put oil in it & it started right up. I ran it for at least 30-40 minutes & it ran & sounded great with no smoking whatsoever. So here's a post of praise for B&S and this engine. But, it appears the co. has gone to OHV's on all its newer offerings. Too bad.