With few exceptions*, every oil you find, whether its for cars, diesel trucks, or motorcycles, is going to have friction modifiers. That's because blends of the last few decades use multifunctional additives which all modify friction. ZDDPs (Zinc and Phos) can modify friction, and calcium sulfonates (detergents) can modify friction. I wish the old myth would die, but its tough--you aren't looking for an oil that "doesn't have friction modifiers." You are looking for an oil that provides enough friction on conventional clutches to pass as JASO MA 1 or 2. There are other tests (specs) that verify sufficient friction for these cellulose clutches, which are met by most diesel oils, which is why those work, too.
*Generally, really boutique oils have extra friction modifiers ($$), and would be too much for a clutch pack. But you won't find those at Walmart or an auto parts store or you'll definitely know when you do because they're upwards of 15/qt. Think Redline, Amsoil, Royal Purple HPS/XPR, ect.
Those that have NO friction modifiers are detergentless motor oils, which no one should use anyway.