THIS IS THE PRESSED ON SPROCKET ON THE CRANK, THAT RUNS THE CAM CHAIN, ON ALL CT90'S FITS: Honda CL90 1967 Honda CM91 1966 Honda CT90 1966, 1976, 1977, 1978, 1979 Honda CT90K1 1969 Honda CT90K2 1970 Honda CT90K3 1971 Honda CT90K4 1972 Honda CT90K5 1974 Honda CT90K6 1975 Honda S90 1965 Honda SL90 1969 Honda ST90 1973 Honda ST90K1 1974 Honda ST90K2 1975 R2065 @ ALIGN CRANK SPROCKET UP THIS WAY