This is all I could find on the internet, maybe try and find the Manuel online for it, it appears to be available.
You can use any good motorcycle 2-stroke oil in the injector tank or premix at 50 to 1. Originally Harley wanted the oil mixed at 25 to 1 in the 1970s but with todays modern oil I mix at 50 to 1.
3. The manual calls for 2-stroke oil in the gearbox but I use SAE30 motor oil in the gearbox. It takes 1.3 pints.