I'm not sure what the x185 means, but if I remember rightly (this is stretching the memory lots of years) the VM came with a tiny main jet: like 90 or 100. You will probably be able to get what you need by using the VM26 model number and ordering what you need. There isn't a whole lot to a "rebuild" on them for that matter: needle & seat, good cleaning, set the floats and tweak the jets up and down. You can move the jet needle up or down, but that's after you're in the ballpark with the main.
Stuck in the seventies- not in the swamp.
(6) Attex, a Hustler, a Super Swamp Fox, (2) Tricarts, (3) Tri-sports, a Sno-co trike, 3 Dunecycles, and a Starcraft! ...so far