Archive Corp. said net income for its fiscal year ended Sept. 25 tripled to $6.1 million from fiscal 1986 net income of $2 million. Revenue was $88.8 million, an increase of 12.7% from $78.8 million a year earlier. Net income in the fourth quarter was $2.3 million, contrasted with a net loss of $845,000 in the corresponding period a year ago. Revenue for the period rose 38% to $25.1 million from $18.2 million. D. Howard Lewis, chairman and president, said the improved net income came largely from "the manufacturing cost reduction program initiated a year ago, coupled with reduced parts cost achieved at our Singapore manufacturing facility." Archive is a Costa Mesa designer, manufacturer and marketer of quarter-inch tape drives used for removable data storage in personal computers and microcomputer systems.