I bought my 82 Seca 550 in 1991 and it is my baby! It has been down a few years and I am slowly fixing her. A few years ago I bought a parts bike and swapped out the entire back wheel to keep the better tire(I was 5 months pregnant and moving to another county in a rush). I also swapped the engine. (I had a bad mechanic try to bore out the seals and f**ked it up) Anyway, I realized that now the sprockets and chain donĀ“t match because I donated the other bike with my new sprockets but still have my new chain, now with old sprockets. The back sprocket is marked \