Genuine Yamaha intake manifold carb joint 2, part number 2A2-13596-00. This part fits the following Yamaha motorcycles.
1977 XS400D - Intake
1978 XS400-2E - Intake
1978 XS400E - Intake
1979 XS400F - Intake
1979 XS400_2F - Intake
1980 XS400G - Intake
1980 XS400SG - Intake
1981 XS400SH - Intake
1981 XS400 (XS400H) - Intake
1982 XS400SJ - Intake