I don't know anything about your motorcycle. I did not see a KH100EL at Partzilla, but there is 77 KH100-B8.
From the cross-reference at partzilla the B8 uses the same carburetor as several other models, including the
KE100 (16001-230)(not sure what years, but I think at least 1976).
There are a couple of other KE100 carburetors listed that might also work, but I don't know if any of those would work with your air cleaner or if a different air cleaner could be used.
see diagrams at Partzilla. then search the part numbers on eebbaayy. then search EB by model & part.
1981 KZ650-CSR. Competition, Sports & Road.