I inherited a Snapper mower who while the previous owner used M1 synthetic oil - it had been over due for an oil change and the oil was black . I re-filled with a straight 30W conventional oil plus I added 25% MMO (13 oz. of 30W and 3oz. of MMO) . I figure I would run this mixture until the end of the season and then dump it and refill with M1 10W 30 and see how she does ...Anybody else use MMO to clean up a "suspect" small engine ?