The Collaborative International Dictionary
yuck factor
yuck factor \yuck factor\, n. a reaction of repugnance or distaste; -- used in discussion of acceptability of proposed new foods, medicines, etc. among potential consumers or patients.
Wiktionary
yuck factor
n. (context often uncountable English) Disgusting part of the nature of something; facet or tendencies (of a thing, idea, etc) to produce a reaction of repugnance or distaste.
Usage examples of "yuck factor".
They were strong and way too fast, and had an enormous yuck factor.
Your average Nipple reader enjoys blood and gore, but there is a disgust threshold that might be defined as the yuck factor.
I know it's high yuck factor, but what if the father-in-law had been up her skirt?