Amsoil saber at 95:1. I had tried others and was getting a similar result at 32:1. Maybe this engine just runs this way. I'm hesitant to keep going down from a 58 to a 55. I don't think I have read of anyone else running a small jet like this. Theres no issues with the 58, it just looks richer than it should be. I'm considering switching to ethanol actually. I have 2 gallons ready. I plan to take a small sample and mix a small amount of oil in it, just to make sure it mixes right. From what I understand amsoil synthetic will mix with it. I'm going to find out. I'm really not worried about any of the common issues with it. It's not beyond my means to repair it and it isn't my main transportation. I'd just be interested in whether or not it runs better. I plan on starting at the 72 jet, if my motor is running rich with a 58, hopefully I can get it spot on with a 72 or 74 with ethanol. I like it personally. I think it burns cleaner and runs cooler.