paint too thin?

yeah i have a urethane single stage paint that i love the color of and it looks good. the only problem is that it is really thin and its hard for me being a novice not to get runs everywhere. the paint is 3-1-1 paint, hardener,reducer. i was wondering if it would be safe to use a little less reducer to not make it so thin? isnt that all reducer does is make it thin enough to spray? thanks,

yup you are correct. are you using mixing cups? you may be putting in to much reducer