I've gotten flack for posting my opinions about oil, but at the risk of placing myself in a position I am relatively comfortable with, here goes: I have tried about 8 different oils in three 30+ year old mopeds (including Motul) and came back to what I used while racing 2-stroke dirt bikes in the 70's, Castrol 2T.
2T at 50:1 and mid-grade gasoline have 3 vintage Italian engines mopeds purring like kittens and never any plug fouling. I also run the same mix in two new chainsaws. All start on the first try every time.