Actually, you can get the same info I can. Your TRX Hondas are 46.3 inches wide by 72 inches long. The KFX450r is 46.1 inches wide and 71 inches long.
You find the YFZ 450 and get back to us. mathematically you may make it. Wanna buy a shoe horn? Maybe some grease to make them slide in?
Let's hear from someone that has actually measured the side to side width of the garage, please.