First, make sure residual oil from the factory testing has been removed by removing the oil fill plug, holding the unit over a drain pan and turning the unit so that the opening is on the bottom. Once drained, fill with ONLY 6 ounces of approved fully synthetic 0W40 oil, Jiffy® Part #4288. Check fill level per procedure. Overfilling your engine with oil may cause your engine to smoke, leak, or be damaged as well as void the original warranty.