Kawasaki must have offered them with optional green or light blue frame colors. Mines factory blue and the 10th digit is an L so it's definitely a 1990. It's completely trashed and beyond destroyed but I'm biting the bullet and doing a full restore on it, currently going through the bottom end and having the top end sleeved for future boring if need be. Seeing this one with a green frame I'll probably go ahead and paint mine green to. Thank for letting us all check it out. (Update) upon disassemble I'd see a few hidden places that still had the factory green on the frame in hard to get to welded areas so mine isn't factory blue but there was a yr the E series had a blue frame with white plastics