Sorry no help. I too just bought a 79....well the serial plate shows it was built 12/79 so I am not sure if it considered a 79 or 80. Anyways I am trying to find an owners/repair manual online. Carbs need set. Same as you though I cant find one anywhere. I have found 79 550 twins and 1980 750 fours. If you have any luck finding more info, please post as I will do the same.