Buckling Problem - Cannot decide what effective length factor (K) values to input to my model, can you help?

I'm working on a 4 columned structural mast and I made a model of it on Sap2000. And Sap2000 gave me great amounts of K factor values, such as 5,7~8,0
That sounds creepy! This tower has 4 columns and spacing is about 2m x 1.2m between. Software doesn't make design calculations for the mentioned columns because of the K factors are so high. Whenever i overwrite K values with 1.0~2.0 it calculates accurately. The question i ask is, which K values i should use for the columns, beams and braces. Is there a way to calculate them accurately?? Thanks for your interests!!!