During time there could be carburetors installed which are from other construction years, from abroad, or else. Visually not identifiable. The problem is: e.g. at the Z900/Z1000 model series for 3 years the VM26 carburetor with 3 different needle jets / jet needles / main jets / slow jets have been sold. Often the VM28 carburetor has been used and then nothing fits together. The same at Honda CB750four, from K1 to F1 there were 4 different needle jets / jet needles / main jets / slow jets combinations with different jet needle positions. This means: First check then get parts.