James Whitman McLamore, a cofounder of Burger King, died at his home in Coral Gables, Fla. He was 70. The cause was lung cancer, according to the Burger King company. Mr. McLamore and a partner, David Edgerton, created a small hamburger shop, called Insta Burger King, in Miami in 1954, a year before Ray Kroc opened his first McDonald's. Three years later, the partners dropped the ''Insta,'' added a flame broiler that Mr. McLamore had designed and created the Whopper. Broiled hamburgers were a quick success, and the shop became the chain that is now second in size only to McDonald's. In 1967, the partners sold the chain to the Pillsbury Company, which is now owned by Grand Metropolitan P.L.C., a conglomerate based in London. Mr. McLamore's influence went beyond the company. Allen J. Bernstein, chairman of the Morton's Restaurant Group, said that, as president of the National Restaurant Association in 1975-76, Mr. McLamore lobbied in Washington on the industry's behalf. Mr. McLamore held a degree in hotel administration from Cornell University. At the University of Miami, he was chairman of the trustees for 10 years and helped raise more than $519 million. In 1990, the University of Miami awarded him an honorary doctorate of humanity. Mr. McLamore is survived by his wife of 49 years, Nancy McLamore; a son, Sterling, of Tampa, Fla.; three daughters, Pamela M. Spence of Crystal Lake, Ill., Lynne M. Maddux of Cookville, Tenn., and Susie M. McCormack of Telluride, Colo.; and eight grandchildren.