Most motors can lay on their side, or back, too, just read the manual or speak to a dealer if your not sure. Hondas usually have a pictogram showing appropriate storage positions. Small motors can then be layed under a work bench, or stored on a shelf. If the carbs drained they can even be stored safely in a basement. Ive also nailed a short 2x to a wall stud of an unfinished wall in the garage/shed, and carried the outside end load to the floor on another 2x. Sort of a very short saw horse using the wall stud for the inside leg, allowing the motor to be tucked up tight to the wall. Or, screw a length of 2x8 along the wall and you can hang several small motors.
But a simple and very strong stand as shown by Dougo, above, can be built from 2x4s and 1/2 inch plywood quite easily.