Question: Does anyone know why Zulu, who played Kono, left the show?
Answer: He was asked to speak at a local organization event but the producer insisted that Jack Lord be also there. It was an event in honor of Hawaiians and that set him off. He used a derogatory name for the Jewish producer and that pretty much ended his stint on the show.
Answer: He was fired. He never really appreciated his character. He felt Kono was portrayed as a big dumb Hawaiian and that the stereotype was racist. He also felt underutilized. He was fired after a heated argument with the show's publicist regarding his character. It seems there's not much details given regarding the incident or the firing, so it's seems possible he upset the show's producers as well.
Bishop73
No he said something derogatory about one of the Jewish producers that's why he was fired.