I ran the engine in on lawn mower oil at 32:1 and put about 2 gallons or 5 l through it then switched to Castrol TTS full synthetic motorcycle oil at 40:1 but when I get the engine back together as it has a new ring and piston I will re run it in for a while but will change my synthetic oil brand as the castrol did not save the bearing, not sure what oil I will use yet?.