Gday I have a 1979 Honda CB650. Have heard many opinions on the best fuel to use for older bikes designed to run on leaded fuel. Some mechanics have told me that the small bottles of lead additive you get over the counter at servos are ok. Some have said they are bad for engines as they cause build up of carbon residue on the pistons. And some other mechanics have told me i should only use high octane unleaded. I am thoroughly confused. :? Is there anyone else on this forum who rides older bikes, and what fuel/additive have they been using? Any advice regarding tuning, etc with high octane unleaded? Thanks guys.