Pate,, Cap and H-man, here it is bolted down with 4" long .25"x20 screws. The visible 6x32 screw is for the throttle rod, I turn the throttle lever, (with the red cap) upside down for the 1.50, as you can see the throttle lever on the engine is quite high. In this picture the engine is one of my favorites, an Irvine Q-.72.