So I have had a Craftsman 917.370693 (7.0 hp B&S I think) for a few years, and as I begin every season, I change the oil. This season is no different, in that when I tip the mower over to drain the oil (air filter up of course), I cant get but 4 or 5 ounces out, and the listed capacity is 20 oz. WTF am I doing wrong? 
ps. A few more facts--1. no drain plug on the bottom, 2. service manual simply calls for a tip over to drain, and 3. dipstick showed full before I went to drain.
ps. A few more facts--1. no drain plug on the bottom, 2. service manual simply calls for a tip over to drain, and 3. dipstick showed full before I went to drain.